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Search: id:A094458
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| A094458 |
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Initial members of 25 consecutive primes in a 5 X 5 spiral wherein the mean of all 12 sums is prime. |
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+0
2
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| 3, 71, 433, 587, 751, 1249, 2213, 2531, 2621, 4177, 4211, 4783, 5749, 5903, 6197, 6569, 6719, 7213, 8101, 8513, 8669, 9091, 10091, 10093, 10151, 10723, 10771, 12373, 12503, 13003, 16217, 17359, 18493, 19429, 20287, 20441, 20479, 22051, 22637
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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Arrange 25 consecutive primes in a 5 X 5 grid wherein YJKLM, XIBCN, WHADO, VGFEP, UTSRQ are the first through 5th horizontal rows of primes. Then sum the rows horizontally, vertically, and along the two main diagonals. Total the 12 sums, divide by 12, and if the mean is integral and prime, adjoin initial prime to the sequence.
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EXAMPLE
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a(1)=3 because 3 is the first of 25 primes arranged in a 5 X 5 grid wherein the mean of all 12 sums is 223, prime.
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CROSSREFS
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Cf. A094459 A094454.
Sequence in context: A108231 A130894 A106894 this_sequence A111649 A073589 A089537
Adjacent sequences: A094455 A094456 A094457 this_sequence A094459 A094460 A094461
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KEYWORD
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easy,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), May 06 2004
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