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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 (list; graph; refs; listen; history; text; internal format)
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
Sequence in context: A254665 A106894 A166449 * A183548 A111649 A349072
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, May 06 2004
STATUS
approved

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Last modified February 29 19:20 EST 2024. Contains 370428 sequences. (Running on oeis4.)