A028883 Primes of the form k^2 - 7.

2, 29, 137, 317, 569, 1289, 2297, 2909, 3593, 4349, 8093, 9209, 11657, 17417, 19037, 24329, 26237, 30269, 34589, 36857, 41609, 46649, 49277, 51977, 57593, 60509, 72893, 93629, 101117, 108893, 129593, 133949, 147449, 152093, 166457, 191837, 202493, 219017, 224669

Offset: 1

Author

Patrick De Geest

Keywords

• nonn
• easy

Comments

Subsequence of primes of A028881. - Michel Marcus, Apr 11 2015

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..3000
• Patrick De Geest, Palindromic Quasipronics of the form n(n+x).

Crossrefs

Cf. A028881, A028882.

Programs

Magma

[a: n in [3..500] | IsPrime(a) where a is n^2-7]; // Vincenzo Librandi, Dec 01 2011

Maple

A028883:=n->`if`(isprime(n^2-7), n^2-7, NULL): seq(A028883(n), n=1..500); # Wesley Ivan Hurt, Apr 11 2015

Mathematica

Select[Range[3, 410]^2 - 7, PrimeQ] (* Harvey P. Dale, Sep 20 2011 *)

PARI

lista(nn) = forprime (n=1, nn, if (issquare(n+7), print1(n, ", "))) \\ Michel Marcus, Apr 11 2015

Formula

a(n) = A028881(A028882(n)). - Elmo R. Oliveira, Apr 22 2025

Extensions

More terms from Michel Marcus, Apr 11 2015