A142173 Primes congruent to 23 mod 39.

23, 101, 179, 257, 491, 569, 647, 881, 1193, 1427, 1583, 1973, 2129, 2207, 2441, 2753, 2909, 3221, 3299, 3533, 3767, 3923, 4001, 4079, 4157, 4391, 4547, 4703, 4937, 5171, 5483, 5639, 5717, 6029, 6263, 6653, 7043, 7121, 7433, 7589, 7823, 7901, 8291, 8369

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(10000) | p mod 39 eq 23 ]; // Vincenzo Librandi, Aug 20 2012

Mathematica

Select[Prime[Range[3000]],MemberQ[{23},Mod[#,39]]&] (* Vincenzo Librandi, Aug 20 2012 *)

PARI

is(n)=isprime(n) && n%39==23 \\ Charles R Greathouse IV, Jul 02 2016

Formula

a(n) ~ 24n log n. - Charles R Greathouse IV, Jul 02 2016