A142821 Primes congruent to 23 mod 61.

23, 389, 877, 1487, 1609, 2341, 2707, 4049, 4903, 5147, 5879, 6367, 6733, 6977, 8563, 8807, 8929, 9173, 9539, 9661, 10271, 11003, 11369, 11491, 12101, 12589, 13687, 13931, 14419, 15761, 16127, 16249, 16493, 16981, 17713, 17957, 19421, 19543, 20641, 21617

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(22000) | p mod 61 eq 23 ] ; // Vincenzo Librandi, Sep 05 2012

Mathematica

Select[Prime[Range[2700]], MemberQ[{23}, Mod[#, 61]] &] (* Vincenzo Librandi, Sep 05 2012 *)
Select[Range[23,22000,61],PrimeQ] (* Harvey P. Dale, Jun 17 2018 *)

PARI

is(n)=isprime(n) && n%61==23 \\ Charles R Greathouse IV, Jul 03 2016

Formula

a(n) ~ 60n log n. - Charles R Greathouse IV, Jul 03 2016