A141974 Primes congruent to 23 mod 28.

23, 79, 107, 163, 191, 331, 359, 443, 499, 751, 863, 919, 947, 1031, 1087, 1171, 1283, 1367, 1423, 1451, 1619, 1759, 1787, 1871, 2011, 2039, 2179, 2207, 2347, 2459, 2543, 2683, 2711, 2767, 2851, 2879, 2963, 3019, 3187, 3271, 3299, 3467, 3607, 3691, 3719

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.

Programs

Magma

[p: p in PrimesUpTo(5000) | p mod 28 eq 23 ]; // Vincenzo Librandi, Aug 17 2012

Mathematica

Select[Prime[Range[1500]],MemberQ[{23},Mod[#,28]]&] (* Vincenzo Librandi, Aug 17 2012 *)
Select[Range[23,4000,28],PrimeQ] (* Harvey P. Dale, Nov 24 2017 *)

PARI

is(n)=isprime(n) && n%28==23 \\ Charles R Greathouse IV, Jul 02 2016

Formula

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