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A027864
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Primes of the form k^2 + (k+1)^2 + (k+2)^2 = 3*(k+1)^2+2.
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11
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5, 29, 149, 509, 677, 1877, 3677, 8429, 9749, 11909, 13469, 17789, 22709, 27077, 28229, 45389, 46877, 53069, 70229, 72077, 81677, 100469, 102677, 114077, 128549, 141269, 154589, 180077, 192029, 195077, 207509, 223589, 230189, 261077, 312989, 340709
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OFFSET
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1,1
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COMMENTS
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The domain of k is not explicit. If the domain is all integers then the sequence A257163 is produced. In this sequence domain is all nonnegative integers. - Michael Somos, Oct 24 2015
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LINKS
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MATHEMATICA
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Select[Table[3n^2+6n+5, {n, 0, 400}], PrimeQ] (* Harvey P. Dale, Oct 22 2016 *)
Select[Table[Total[Range[n, n+2]^2], {n, 0, 500}], PrimeQ] (* Harvey P. Dale, May 23 2021 *)
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PROG
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(Python)
from sympy import isprime
print(list(filter(isprime, (3*k**2+6*k+5 for k in range(350))))) # Michael S. Branicky, May 29 2021
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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