A141925 Primes congruent to 21 mod 23.

67, 113, 251, 389, 619, 757, 941, 1033, 1171, 1217, 1447, 1493, 1723, 1861, 1907, 1999, 2137, 2459, 2551, 2689, 3011, 3517, 3701, 3793, 3931, 4253, 4391, 4483, 4621, 4759, 4943, 5081, 5449, 6047, 6277, 6323, 6553, 6599, 6691, 6737, 6829, 6967, 7013, 7151

Offset: 1

Author

N. J. A. Sloane, Jul 11 2008

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000040, A141926.

Programs

Magma

[p: p in PrimesUpTo(9000) | p mod 23 eq 21 ]; // Vincenzo Librandi, Aug 16 2012

Mathematica

Select[Range[21,20000,23],PrimeQ] (* Vladimir Joseph Stephan Orlovsky, May 18 2011 *)

PARI

is(n)=isprime(n) && n%23==21 \\ Charles R Greathouse IV, Jul 02 2016

Formula

a(n) ~ 22n log n. - Charles R Greathouse IV, Jul 02 2016