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View:  Topic list, Topic summary « Newer  Topics 11 - 20 of 11019  Older »

primes in the arithmetic sequence 1, 31, 61, 91, 121, ... 30k+1 ... 
  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 »
By David Bernier  - Apr 22 - 6 new of 6 messages    

flashlight following path traced out by Peano-type curve, Kakeya needle problem 
  The 2D Kakeya needle problem asks how "small" a compact set K in R^2 can be if K contains a unit length line segment [A, B] in every direction in the plane. The smallness can be evaluated by the Lebesgue measure of K, or some finer notion of smallness (Hausdorff dimension). For example, with a circle of radius 100 and a point Q... more »
By David Bernier  - Apr 21 - 5 new of 5 messages    

DOW at 14,613.48 .... irrational exuberance? 
  In article <kk4e7m$ks...@dont-email.me>, ... ... Didn't you notice the "...." after it? -- Richard
By Richard Tobin  - Apr 10 - 1 new of 1 message    

Let's give away some goals 
  [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.
By Matifutbol  - Apr 6 - 1 new of 1 message    

AfmToPfm 
  AfmToPfm [link] AV Voice Changer Software [link] 24x24 Free Application Icons [link] 3proxy [link] History Cleaner [link] AfmToPfm
By Archibald theo thi  - Mar 31 - 1 new of 1 message    

Jim Hodges, 6StringStu, Six String Stu, James Stuart Hodges 1793 
  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 »
By Trailer Trash Suzie  - Mar 20 - 1 new of 1 message    

SOLUTIONS MANUAL: Parallel Programming: Techniques and Applications Using Networked Workstations and Parallel Computers (2nd Ed., Barry Wilkinson & Michael Allen) 
  I have solution manual for these textbooks .. They are all in PDF format .. If you are interested in any one, please send an email to macmorino(at)gmail(dot)com .. Please I CHARGE for sending the PDF files. Here are the solution manual to some titles.. SOLUTIONS MANUAL: A First Course in the Finite Element Method, 4th... more »
By Mac Morino  - Mar 19 - 1 new of 1 message    

Question on a kind of metric 
  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 »
By JMF  - Mar 16 - 8 new of 8 messages    

Calculating the area of a closed 3-D path or ring 
  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 »
By Math Guy  - Mar 12 - 22 new of 22 messages    

Differences = 3n 
  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 »
By Pavel314  - Mar 6 - 3 new of 3 messages    

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