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A269787
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Primes p such that 2*p + 43 is a square.
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1
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3, 19, 199, 523, 739, 991, 1279, 2791, 3259, 6823, 9091, 12619, 13591, 15643, 17839, 32491, 34039, 37243, 40591, 63703, 68059, 72559, 79579, 86923, 89443, 105319, 110899, 137791, 144163, 153991, 160723, 171091, 178183, 192799, 196543, 200323, 211879, 219763
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OFFSET
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1,1
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COMMENTS
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Primes of the form 2*k^2 + 2*k - 21.
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LINKS
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MATHEMATICA
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Select[Prime[Range[25000]], IntegerQ[Sqrt[2 # + 43]] &]
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PROG
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(Magma) [p: p in PrimesUpTo(300000) | IsSquare(2*p + 43)];
(PARI) lista(nn) = forprime(p=2, nn, if (issquare(2*p+43), print1(p, ", "))); \\ Michel Marcus, Mar 22 2016
(Python)
from gmpy2 import is_prime, is_square
for p in range(3, 10**6, 2):
if(not is_square(2*p+43)):continue
elif(is_prime(p)):print(p)
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CROSSREFS
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Cf. similar sequences listed in A269784.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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