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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

Table of n, a(n) for n=1..43.

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.)