A141893 Primes congruent to 11 mod 21.

11, 53, 137, 179, 263, 347, 389, 431, 557, 599, 641, 683, 809, 977, 1019, 1061, 1103, 1187, 1229, 1439, 1481, 1523, 1607, 1733, 1901, 2027, 2069, 2111, 2153, 2237, 2447, 2531, 2657, 2699, 2741, 2909, 3119, 3203, 3329, 3371, 3413, 3539, 3581, 3623, 3833, 3917

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, A124826.

Programs

Magma

[ p: p in PrimesUpTo(5000) | p mod 21 eq 11 ]; // Vincenzo Librandi, Apr 05 2011

Mathematica

Select[Range[11,5000,21],PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 04 2011 *)

PARI

is(n)=isprime(n) && n%21==11 \\ Charles R Greathouse IV, Jul 02 2016

Formula

a(n) ~ 12n log n. - Charles R Greathouse IV, Jul 02 2016