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 A269785 Primes p such that 2*p + 23 is a square. 1
 13, 29, 73, 101, 353, 409, 601, 673, 829, 1093, 1289, 1613, 1973, 2801, 2953, 3109, 3433, 4129, 4889, 5501, 6373, 6833, 7069, 7309, 8053, 9649, 9929, 10501, 13933, 16369, 18229, 19001, 20593, 21001, 25301, 26209, 26669, 28549, 30493, 31489, 33013, 33529, 36709 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes of the form 2*k^2 + 2*k - 11. LINKS MATHEMATICA Select[Prime[Range[5000]], IntegerQ[Sqrt[2 # + 23]] &] PROG (MAGMA) [p: p in PrimesUpTo(50000) | IsSquare(2*p + 23)]; (PARI) lista(nn) = forprime(p=2, nn, if (issquare(2*p+23), 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+23)):continue     elif(is_prime(p)):print(p) # Soumil Mandal, Apr 07 2016 CROSSREFS Cf. A000040. Subsequence of A002144, A045433. Cf. similar sequences listed in A269784. Sequence in context: A139838 A217197 A141196 * A123571 A209989 A269515 Adjacent sequences:  A269782 A269783 A269784 * A269786 A269787 A269788 KEYWORD nonn AUTHOR Vincenzo Librandi, Mar 22 2016 STATUS approved

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Last modified January 29 14:07 EST 2020. Contains 331338 sequences. (Running on oeis4.)