A110913 Numbers n such that 23*n^2 - 49 is prime.

2, 8, 10, 16, 20, 22, 34, 36, 46, 52, 58, 68, 72, 74, 78, 80, 102, 104, 122, 130, 132, 134, 148, 152, 156, 162, 164, 166, 186, 198, 200, 204, 208, 212, 214, 250, 254, 264, 270, 278, 284, 302, 318, 320, 328, 332, 338, 340, 358, 362, 366, 380, 382, 390, 396, 440

Offset

1,1

Comments

All the numbers in this sequence are even.

Links

G. C. Greubel, Table of n, a(n) for n = 1..5000

Example

If n=80 then(23*n^2) - 49 = 147151 (prime).

Mathematica

Select[Range[700], PrimeQ[23*#^2 - 49] &] (* G. C. Greubel, Oct 19 2017 *)

Prog

(Magma) [n: n in [2..100000] |IsPrime((23*n^2)-49)] - Vincenzo Librandi, Nov 13 2010
(PARI) is(n)=isprime(23*n^2-49) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A047467 A079599 A126002 * A038638 A226831 A197115

Adjacent sequences: A110910 A110911 A110912 * A110914 A110915 A110916

Keyword

nonn,easy

Author

Parthasarathy Nambi, Oct 03 2005

Status

approved