[math-fun] 45th and 46th Known Mersenne Primes Found!!!!???
45th and 46th Known Mersenne Primes Found!!!!??? On August 23rd, a computer reported finding a new Mersenne prime to the server! Because I was on vacation, verification did not begin until the 26th. Two verification runs are in progress. Estimated completion is September 10th or 11th. Check back here for updates! Amazingly, on September 6th, another computer claims finding a new Mersenne prime!! Independent verification has begun. look for updates at: http://www.mersenne.org/
It's easy to make a square with numbers 1-16 in order. .1 .2 .3 .4 | .9 .4 .. .. .5 .6 .7 .8 | .. .. .. .. .9 10 11 12 | .. .. .. .. 13 14 15 16 | .. .. .. .. Add a second square, so that for any pair of numbers 1 to 16, the chosen pair will be in a row, column, or main diagonal in exactly one of the two squares. The first row starts 9, then 4. What is this square? Hint: it's a magic square. Ed Pegg Jr
Solution: 9 4 6 15 7 14 12 1 16 5 3 10 2 11 13 8 Not only a magic square, this is a Graeco-Latin square, with 4*A + B + 1: A B 2 0 1 3 0 3 1 2 1 3 2 0 2 1 3 0 3 1 0 2 3 0 2 1 0 2 3 1 1 2 0 3 Christian. -----Message d'origine----- De : math-fun-bounces@mailman.xmission.com [mailto:math-fun-bounces@mailman.xmission.com] De la part de Ed Pegg Jr Envoyé : dimanche 7 septembre 2008 21:07 À : math-fun Objet : [math-fun] A t-design that forces a magic square. It's easy to make a square with numbers 1-16 in order. .1 .2 .3 .4 | .9 .4 .. .. .5 .6 .7 .8 | .. .. .. .. .9 10 11 12 | .. .. .. .. 13 14 15 16 | .. .. .. .. Add a second square, so that for any pair of numbers 1 to 16, the chosen pair will be in a row, column, or main diagonal in exactly one of the two squares. The first row starts 9, then 4. What is this square? Hint: it's a magic square. Ed Pegg Jr _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
participants (3)
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Christian Boyer -
Ed Pegg Jr -
Robert Baillie