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 A269790 Primes p such that 2*p + 79 is a square. 1
 73, 181, 2341, 4861, 6121, 9901, 12601, 18973, 20161, 26641, 47701, 51481, 59473, 61561, 68041, 79561, 81973, 84421, 94573, 110881, 157321, 185401, 192781, 207973, 231841, 244261, 248473, 270073, 292573, 335341, 365473, 440821, 446473, 452161, 475273 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes of the form 2*k^2 + 2*k - 39. 2*p + h is not verified if h is an odd prime that belongs to A055025 because (2*h-1)/2 is a multiple of 2. LINKS EXAMPLE a(1) = 73 because 2*73 + 79 = 225, which is a square. MATHEMATICA Select[Prime[Range[50000]], IntegerQ[Sqrt[2 # + 79]] &] PROG (MAGMA) [p: p in PrimesUpTo(600000) | IsSquare(2*p+79)]; (PARI) lista(nn) = {forprime(p=2, nn, if(issquare(2*p + 79), print1(p, ", "))); } \\ Altug Alkan, Mar 24 2016 (Python) from sympy import isprime from gmpy2 import is_square for p in xrange(0, 1000000):     if(is_square(2*p+79) and isprime(p)):print(p) # Soumil Mandal, Apr 03 2016 CROSSREFS Cf. A000040. Subsequence of A002144, A045433, A061237, A068228. Cf. similar sequences listed in A269784. Sequence in context: A044786 A244774 A142550 * A142741 A088199 A140010 Adjacent sequences:  A269787 A269788 A269789 * A269791 A269792 A269793 KEYWORD nonn AUTHOR Vincenzo Librandi, Mar 24 2016 STATUS approved

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Last modified January 22 01:33 EST 2019. Contains 319351 sequences. (Running on oeis4.)