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primes in the arithmetic sequence 1, 31, 61, 91, 121, ... 30k+1 ...
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I was looking for a simple arithmetic sequence with
many primes "crowded together", i.e. quasi-consecutive ...
Suppose we let n = 1,097,495,500,000 ; then I get this:
n+19941 is prime, n+19971 is prime, n+20001 is prime,
n+20031 is prime, n+20061 is prime, n+20091 is prime,
n+20121 is composite,... more »
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Let's give away some goals
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[link]
Close packing. Geometry. Organizers of Brazil 2014 FIFA World Cup want to give away some official balls. We face a close-packing problem in order to know if we can fill Maracana stadium with enough balls to satisfy the Championship organizers' wishes.
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Jim Hodges, 6StringStu, Six String Stu, James Stuart Hodges 1793
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1793
James S. Hodges
577 SW Dexter Cir, Apt 201
1442 SW Haygood Loop, Apt 101
Lake City, FL 32025
(386) 438-8968
Local PD: (386) 752-4344
...Newsgroups: alt.social-security-disability
..." Of the three felonies on my record,
1: Violation of the Mann act (federal kidnapping...)....
2nd Felony arrest Homicide........... more »
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Question on a kind of metric
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I don't suppose this is a particularly recreational problem, but
somebody might be interested in it. It actually comes from my work.
I'm calculating a kind of weighted average of a whole bunch of values.
In plain English, it's "The sum of various percentages of the values
divided by the sum total."... more »
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Calculating the area of a closed 3-D path or ring
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Looking for some thoughts about how to understand this problem.
A closed loop (an irregular ring) is defined by a set of n points in
space.
Each point has an (x,y,z) coordinate. The points are not co-planar. Typically, this ring would approximate the perimeter of a horse saddle,
or a potato chip. The number of points (n) is typically from 6 to 12... more »
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Differences = 3n
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We have a weather center gizmo in the livingroom that gives the outside temperature and humidity as well as the inside temperature and humidity. These four numbers are displayed in a 2x2 grid and change throughout the evening if the wind direction shifts or if we throw another log into the woodstove. Yesterday evening, I noticed that the differences between any two of the numbers were all divisible by three.... more »
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