2,7,1,8,2,1,8 sequence puzzle
prdwong
8, 2, 1, 8". Somebody must have seen this before...
A quick google of the sequence gives:
http://members.tripod.com/~bz/riddles.html
http://www.geocities.com/master_galaxy_2001/riddle_of_the_week.htm
But both websites seem to be defunct, and at any rate, neither of them
give the answer.
The On-Line Encyclopedia of Integer Sequences doesn't have a match, so
it's unlikely this is math based. Judging from the two websites above,
it seems to be more of a riddle.
Anybody know the answer?
Prakash
> My friend asked me to find the next number in the sequence: "2, 7, 1,
> 8, 2, 1, 8". Somebody must have seen this before...
Spoiler
Spoiler
Answer : 2
P
p.s. 2 7 1 8 2 1 8 2 8 2
Steve Fry
Prakash wrote:
> prdwong wrote:
>
> > My friend asked me to find the next number in the sequence: "2, 7, 1,
> > 8, 2, 1, 8". Somebody must have seen this before...
>
>
> Answer : 2
>
>
> p.s. 2 7 1 8 2 1 8 2 8 2
>
>
I don't follow your reasoning.
You aren't thinking these are the sequence of digits making up e are you?
Over thirty years ago I set about memorizing as many digits of pi and e as I
could.
I can still recite from memory 24 digits of e and 36 digits of pi.
These digits do not match either.
-- Steve F.
Alan Morgan
If you swap the last two digits of the original puzzle then they do match the digits
of e. My guess would be that either the original poster or his/her friend made a
transcription error.
Alan
--
Defendit numerus
Mark Brader
P.R.D. Wong:
>>>> My friend asked me to find the next number in the sequence: "2, 7, 1,
>>>> 8, 2, 1, 8". Somebody must have seen this before...
Alan Morgan:
> If you swap the last two digits of the original puzzle then they do
> match the digits of e. My guess would be that either the original
> poster or his/her friend made a transcription error.
Agreed.
And the next question is, where has this sequence of digits (to be
exact, the first 10 of them) been in the news very recently?
--
Mark Brader, Toronto "Those who cannot Google the past are destined
m...@vex.net to repost it." -- Huey Callison
Bill Smythe
polynomial to it. So ANY number could be the correct answer. It's just a
question of guessing what the puzzle author had in mind.
That's why I hate these puzzles. To illustrate the futility of it all, one
of my favorites is:
What is the next number in the sequence 1, 3, 5, 7, .... ?
The answer? 8. Those are the numbers with the letter E in their names.
Bill Smythe
Ted S.
news:10961t2...@corp.supernews.com:
> Agreed.
>
> And the next question is, where has this sequence of digits (to be
> exact, the first 10 of them) been in the news very recently?
Somebody got the phone number (271) 828-2818?
--
Ted <fedya at bestweb dot net>
The way I see it, you raised three children who could knock out and hog-
tie a perfect stranger, you must be doing *something* right.
Marge Simpson, <http://www.snpp.com/episodes/7G01.html>
Mark Brader
> > And the next question is, where has this sequence of digits
> > been in the news very recently?
> Somebody got the phone number (271) 828-2818?
Well, according to Google that's a real phone number, belonging to a
Muslim students' association in Clinton, New York, but I don't think
it's been in the news very recently -- it doesn't turn up in Google
News. But if you search for the digits in the correct form relevant
to my question, you will find hits in Google News.
--
Mark Brader | "What a strange field. Studying beings instead of mathematics.
Toronto | Could lead to recursive problems in logic."
m...@vex.net | -- Robert L. Forward (The Flight of the Dragonfly)
My text in this article is in the public domain.
Greg
>
>P.R.D. Wong:
>>>>> My friend asked me to find the next number in the sequence: "2, 7, 1,
>>>>> 8, 2, 1, 8". Somebody must have seen this before...
>
>Alan Morgan:
>> If you swap the last two digits of the original puzzle then they do
>> match the digits of e. My guess would be that either the original
>> poster or his/her friend made a transcription error.
>
>Agreed.
>
>And the next question is, where has this sequence of digits (to be
>exact, the first 10 of them) been in the news very recently?
SPOILER
The wonderful geeks at Google used this figure as the value of their
IPO ($2,718,281,828).
--
Greg
phobos78-marslink-net
Replace dashes and move in by 1 planet to reply.
The Qurqirish Dragon
>polynomial to it. So ANY number could be the correct answer. It's just a
>question of guessing what the puzzle author had in mind.
True. That is why I believe that when you answer a puzzle like this, you should
give your reasoning.
For example, in an exam on sequences and series, a bad question is "find the
next three terms in the sequence..."
Much better is "Find the next three terms, and give a general rule for the nth
term of ..."
Usually there are very few answers with logical choices that don't take a long
time to find. For example, an interpolating polynomial for 6 terms can take
quite a while to calculate by hand.
>That's why I hate these puzzles. To illustrate the futility of it all, one
>of my favorites is:
>
>What is the next number in the sequence 1, 3, 5, 7, .... ?
>
>The answer? 8. Those are the numbers with the letter E in their names.
I think these series are more interesting if you ask "what is the rule for the
terms in the sequence starting ...", and for any guess, you either say it is
correct, or you give the first term that violates the rule.
Example:
original sequence starts: "0,1,3..." (original idea is An=nC2, starting from
n=1. This is, of course, the triangular numbers.)
first guess: "each number is the previous number squared, plus 1."
response: "no, the 4th term is 6, not 10"
and so on.
This makes it a deduction problem more than a random guess problem.
I usually like sequence problems, but I only like them if there is a relatively
simple answer (simple meaning a reasonable person would have thought of it.)
This would be an unfair puzzle:
find the next term in the sequence:
7,0,7,4,1,3,...
(hint: there are 24 terms total)
The answer, "of course" is the check digit of the UPC codes for the PS2 games
on my shelf. Nobody would ever get the rule (although there is a 1 in 11 chance
you could get it by chance- though I doubt anyone would guess x)
--
The Qurqirish Dragon, posting from his home somewhere in Ohlam.
--==<<{{ UDIC }}>>=--
Remember- my address is no laughing matter
Mark Brader
>> And the next question is, where has this sequence of digits
>> been in the news very recently?
by searching on the form of it that he gave.
--
Mark Brader, Toronto | "You keep using that word. I do not think it means
m...@vex.net | what you think it means." -- The Princess Bride
Stewart Gargis
"Mark Brader" <m...@vex.net> wrote in message
news:10968uc...@corp.supernews.com...
> Mark Brader:
> > > And the next question is, where has this sequence of digits
> > > [the correct digits of e] (to be exact, the first 10 of them)
> > > been in the news very recently?
>
> Ted Schuerzinger:
> > Somebody got the phone number (271) 828-2818?
>
> Well, according to Google that's a real phone number, belonging to a
> Muslim students' association in Clinton, New York, but I don't think
> it's been in the news very recently -- it doesn't turn up in Google
> News. But if you search for the digits in the correct form relevant
> to my question, you will find hits in Google News.
s
p
o
i
l
e
r
It's the proposed maximum aggregate offering price in the S-1 filing by
those mischievous dudes at Google.
prdwong
Unfortunately, I did ask my friend after posting whether he had made a
transcription error...otherwise it would very obviously be e
(2718281828459...), or alternatively, (Pi^4 + Pi^5)^(1/6)
(2718281808611...).
He assured me that it was not a transcription error. 2, 7, 1, 8, 2, 1,
8, ? is the correct sequence, and he sent the pattern along with his
solution to John Nash and the head of math dept at Princeton, who
agreed with him. (This was 1-2 years ago). So it's not anything to do
with current events either (sorry, can't tell whether you guys are
joking about Google IPO or not... :)
I realize that there are infinitely many possible solutions, but quite
obviously there is only one solution that my friend of thinking of,
and it can't be something truly random/obscure.
The other solution I tried to give him was -201, -1442, -5641, which
you get from f(x) = -17/80 x^6 + 953/240 x^5 - 1343/48 x^4 + 4403/48
x^3 - 16537/120 x^2 + 753/10 x + 2. (So f(0) = 2, f(1) = 7, f(2) =
1...etc...) But he rejected that too.
Some other clues he gave me: It's not intensively mathematical, but it
doesn't have anything to do with letters either. The sequence can be
generated to infinite length, and all the subsequent members are one
digit numbers.
If anybody has any more ideas, I'd appreciate it.
Jeffrey Turner
The lengths of the words of some book or document of interest or a
song?
--Jeff
--
Let me make the superstitions of a nation
and I care not who makes its laws or its
songs either. -- Mark Twain
The trouble with the world is that the
stupid are cocksure and the intelligent
are full of doubt. --Bertrand Russell
Those who do not learn from history are
doomed to repeat it. --George Santayana
Unthinking respect for authority is the
greatest enemy of truth. --Albert Einstein
Freedom's just another word for nothing
left to lose. --Kris Kristofferson
Larry C.
wrote:
>prdwong wrote:
>> Some other clues he gave me: It's not intensively mathematical, but it
>> doesn't have anything to do with letters either. The sequence can be
>> generated to infinite length, and all the subsequent members are one
>> digit numbers.
>>
>> If anybody has any more ideas, I'd appreciate it.
>
>The lengths of the words of some book or document of interest or a
>song?
>
>--Jeff
I don't know of any song, book or document that is of infinite length. I
know some seem like they are that long...
matt
"Larry C." <ldco...@sanspamblock.rr.com> wrote in message
news:lc0i90leqe5cer9s9...@4ax.com...
not many either where no word is ten letters long or more
in order to scotch the feeling that it is a typo of e - could your friend
give us the next couple of digits
regards
matthew
Bob Harris
> I don't know of any song, book or document that is of infinite length. I
> know some seem like they are that long...
I believe they had one on the cartoon series Futurama. It was titled
"Aleph-Naught Bottles of Beer in the Wall" (hopefully I spelled that
right).
Bob H
The Qurqirish Dragon
How about "This is the song that does not end..."
As a bonus, that song has no words of more than 9 letters long (I think 7
letters is the longest word in it, although there are a few words of that
length)
David Eppstein
qurqi...@aol.comHAHA (The Qurqirish Dragon) wrote:
> >I believe they had one on the cartoon series Futurama. It was titled
> >"Aleph-Naught Bottles of Beer in the Wall" (hopefully I spelled that
> >right).
>
> How about "This is the song that does not end..."
One my daughter has been singing lately:
I know a song that gets on everybody's nerves
Everybody's nerves, everybody's nerves
I know a song that gets on everybody's nerves
and this is how it goes:
I know a song that gets on everybody's nerves
Everybody's nerves, everybody's nerves
I know a song that gets on everybody's nerves
and this is how it goes:
...
--
David Eppstein http://www.ics.uci.edu/~eppstein/
Univ. of California, Irvine, School of Information & Computer Science
prdwong
I asked my friend what the solution was, and this is what he said:
Take the first 5 numbers. The middle number is 1.
Take the next 5 numbers. The middle number is 8.
etc...
So the answer is 2, 7, 1, 8, 2, 1, 8, 2, 1, 8, 2, 1, 8, ....
I officially declare this to be stupid. Then why not just do 1, 8, 2,
1, 8, 2, etc...? Ugh...anyways, sorry to waste everybody's time.
Arthur J. O'Dwyer
On Thu, 6 May 2004, prdwong wrote:
>
> prd...@yahoo.com (prdwong) wrote...
> > My friend asked me to find the next number in the sequence: "2, 7, 1,
> > 8, 2, 1, 8". Somebody must have seen this before...
>
>
> Take the first 5 numbers. The middle number is 1.
> Take the next 5 numbers. The middle number is 8.
> etc...
>
> So the answer is 2, 7, 1, 8, 2, 1, 8, 2, 1, 8, 2, 1, 8, ....
>
> I officially declare this to be stupid.
No, no, no. Just tell your friend that he had the right idea
with taking 5-number windows, but his proposed continuation is
wrong: the correct answer is
2, 7, 1, 8, 2, 1, 8, 2, 1, 7, 2, 8, 1, 7, 2, 1, 8, ...
The complete explanation of this sequence can be found on page
42 of Nugry's Treasury, right between "three legs at morning"
and "traveling knapsack problem."
-Arthur
Ed Murphy
Oh, aye. Or, in a different vein of cruelty, take the approach
recommended in a book I read as a kid (I forget the name). I will
proceed to sum it up from memory.
There are trivia freaks, and there are trivia pain-in-the-asses
(TPAs). The way to deal with TPAs is to deliver a Sucker Punch
(a relatively easy question that feeds their ego), followed by
a Knock-Out (nigh-impossible, deflates it right quick).
SP: In what country was Stalin born?
KO: What was his birth name?
SP: In the Star Trek universe, who invented warp drive?
KO: In what year was it invented?
SP: In _Gone with the Wind_, what was the name of the O'Hara residence?
KO: What was the name of the Wilkes residence?
Dgates
wrote:
Weird, I'm only sure of one of the six questions! :-o
--
dga...@spamfreelinkline.com
Mark Brader
> There are trivia freaks, and there are trivia pain-in-the-asses
> (TPAs). The way to deal with TPAs is to deliver a Sucker Punch
> (a relatively easy question that feeds their ego), followed by
> a Knock-Out (nigh-impossible, deflates it right quick).
And the way to deal with *these* people is to answer the second question.
> SP: In what country was Stalin born?
Georgia.
> KO: What was his birth name?
Joseph Dzugashvili. Sheesh.
> SP: In the Star Trek universe, who invented warp drive?
Zefram Cochrane.
> KO: In what year was it invented?
About 2160, wasn't it?
> SP: In _Gone with the Wind_...
Who cares?
--
Mark Brader, Toronto | "Gwyneth Paltrow always says I'm a
m...@vex.net | shameless name dropper" -- Roger Ford
Dan Tilque
> Ed Murphy writes:
>
>> SP: In the Star Trek universe, who invented warp drive?
>
> Zefram Cochrane.
This one is the "who cares?" for me. I've done everything I can
to put ST out of my mind. Now I'm going to have to forget this
factoid.
>
>> SP: In _Gone with the Wind_...
>
> Who cares?
No, no, no! The appropriate line starts with "Frankly..."
--
Dan Tilque
Matthew Russotto
Ed Murphy <emur...@socal.rr.com> wrote:
>Oh, aye. Or, in a different vein of cruelty, take the approach
>recommended in a book I read as a kid (I forget the name). I will
>proceed to sum it up from memory.
>
>There are trivia freaks, and there are trivia pain-in-the-asses
>(TPAs). The way to deal with TPAs is to deliver a Sucker Punch
>(a relatively easy question that feeds their ego), followed by
>a Knock-Out (nigh-impossible, deflates it right quick).
>
>SP: In what country was Stalin born?
>KO: What was his birth name?
Too easy: Georgia, and Djugashvili. I knew the latter but had to look
up the spelling. Might want to ask for his patronymic as a knockout.
Matthew Russotto
Mark Brader <m...@vex.net> wrote:
>Ed Murphy writes:
>> There are trivia freaks, and there are trivia pain-in-the-asses
>> (TPAs). The way to deal with TPAs is to deliver a Sucker Punch
>> (a relatively easy question that feeds their ego), followed by
>> a Knock-Out (nigh-impossible, deflates it right quick).
>
>And the way to deal with *these* people is to answer the second question.
>
>> SP: In what country was Stalin born?
>
>Georgia.
>
>> KO: What was his birth name?
>
>Joseph Dzugashvili. Sheesh.
Yeah, but what was his patronymic?
>> SP: In the Star Trek universe, who invented warp drive?
>
>Zefram Cochrane.
>
>> KO: In what year was it invented?
>
>About 2160, wasn't it?
I'm pretty sure there were at least two different dates given.
>
>> SP: In _Gone with the Wind_...
>
>Who cares?
It was Tara, but I only care at all because my sister was named after it.
Alan Morgan
[totally inane puzzle snipped]
>Oh, aye. Or, in a different vein of cruelty, take the approach
>recommended in a book I read as a kid (I forget the name). I will
>proceed to sum it up from memory.
>
>There are trivia freaks, and there are trivia pain-in-the-asses
>(TPAs). The way to deal with TPAs is to deliver a Sucker Punch
>(a relatively easy question that feeds their ego), followed by
>a Knock-Out (nigh-impossible, deflates it right quick).
>
>SP: In what country was Stalin born?
>KO: What was his birth name?
>
>SP: In the Star Trek universe, who invented warp drive?
>KO: In what year was it invented?
>
>SP: In _Gone with the Wind_, what was the name of the O'Hara residence?
>KO: What was the name of the Wilkes residence?
SP: What was the first movie to win an Academy Award?
KO: Who was the only person to win both an Academy Award and a Nobel Prize?
I used this question on a person who, unwisely, bragged that he knew every
bit of Academy Award trivia there was.
Alan
--
Defendit numerus
Ted S.
wrote in news:9G2dnST1TtI...@speakeasy.net:
>>> KO: What was his birth name?
>>
>>Joseph Dzugashvili. Sheesh.
>
> Yeah, but what was his patronymic?
Vissarionovich. :-)
Mark Brader
> SP: What was the first movie to win an Academy Award?
> KO: Who was the only person to win both an Academy Award and a Nobel Prize?
Oh pshaw, you've got those two backwards. To answer the first one
you'd have to know *what order* the various awards were presented in
at the first Academy Award ceremony, and that's something I've never
seen listed anywhere.
Unless of course you specifically meant the Academy Award for "Best
Picture, Production" -- but usually one says that "the movie won
6 Oscars", not "the movie and various people involved with it won
a total of 6 Oscars". So I don't think that interpretation works.
--
Mark Brader | "For the stronger we our houses do build,
Toronto | The less chance we have of being killed."
m...@vex.net | -- William McGonagall, "The Tay Bridge Disaster"
David K. Lewis
>
> >SP: In the Star Trek universe, who invented warp drive?
> >KO: In what year was it invented?
I think the SP above is more of a KO. I know the intended
answer is Zephrem Cocharan, but that isn't the correct
answer since warp drive was around long before him.
It makes me wonder if they ever said who did invent
it...
You can't even re-word it to say "What earthling" "....for
the federation." since in the 60's Zephrem wasn't an earthling,
but from Alpha Centari (something they changed for the 90's
movies) and there was no federation when he invented it
(at least in the movie version, not sure about the 60's
version).
Dave.
Alan Morgan
Mark Brader <m...@vex.net> wrote:
>Alan Morgan writes:
>> SP: What was the first movie to win an Academy Award?
>> KO: Who was the only person to win both an Academy Award and a Nobel Prize?
>
>Oh pshaw, you've got those two backwards. To answer the first one
>you'd have to know *what order* the various awards were presented in
>at the first Academy Award ceremony, and that's something I've never
>seen listed anywhere.
>
>Unless of course you specifically meant the Academy Award for "Best
>Picture, Production" -- but usually one says that "the movie won
>6 Oscars", not "the movie and various people involved with it won
>a total of 6 Oscars". So I don't think that interpretation works.
That is what I intended, so you'll just have to accept the fact that I
was being sloppy. Nyah.
I was not aware of the fact that two Best Picture awards were given out
that first year (to Wings, for Best Production, and Sunrise, for Best
Unique and Artistic Picture. Henceforth I will use "Sunrise", instead of
"Wings", as my answer to this question). I'm not sure it makes sense
to say which was first, as the awards had been announced some weeks
before and the Academy banquet was just to honor them.
Alan
--
Defendit numerus
Ed Murphy
Ack, good point. "What human" ought to work.
Ed Murphy
The book includes a comment like "anyone who even *tries* to pronounce
this is a TF, not a TPA, so lay off already".
David K. Lewis
Only if you think someone from Alpha Centari is a human,
its likely their genetics would be different...
Dave.
Mark J. Tilford
Zephrem was human. I can't recall whether he'd been born on earth but
transported to AC via freezer ships, or if he was just descended from people
who had done so.
--
------------------------
Mark Jeffrey Tilford
til...@ugcs.caltech.edu
David K. Lewis
I've seen various timelines, where he was human and traveled to
AC after inventing warp, where he went there on a sleeper ship,
and where he was an alpha centaurian as a separate culture and
race from earth...
The point is that I wouldn't call the original question an SP :)
Dave.