

A094458


Initial members of 25 consecutive primes in a 5 X 5 spiral wherein the mean of all 12 sums is prime.


1



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
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OFFSET

1,1


LINKS



FORMULA

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.


EXAMPLE

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.


CROSSREFS



KEYWORD

easy,nonn


AUTHOR



STATUS

approved



