A045327 Primes congruent to {2, 3, 4} mod 5.

2, 3, 7, 13, 17, 19, 23, 29, 37, 43, 47, 53, 59, 67, 73, 79, 83, 89, 97, 103, 107, 109, 113, 127, 137, 139, 149, 157, 163, 167, 173, 179, 193, 197, 199, 223, 227, 229, 233, 239, 257, 263, 269, 277, 283, 293, 307

Offset

1,1

Comments

This sequence also happens to be one of impossible prime factors of 2^(2^n)+7. To form the sequence one uses PARI {p(n) = (2^(2^n) + 7)/p} and the run the program up to only Eulerphi(Eulerphi(p)). - A.K. Devaraj, Dec 14 2009

Links

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

Formula

a(n) ~ (4/3) n log n. - Charles R Greathouse IV, Aug 07 2012

Mathematica

Select[Prime[Range[300]], MemberQ[{2, 3, 4}, Mod[#, 5]]&] (* Vincenzo Librandi, Aug 07 2012 *)

Prog

(Magma) [ p: p in PrimesUpTo(600) | p mod 5 in {2, 3, 4} ]; // Vincenzo Librandi, Aug 07 2012
(PARI) select(n->n%5>1, primes(50)) \\ Charles R Greathouse IV, Aug 07 2012

Crossrefs

Cf. A000040.

Sequence in context: A363450 A336378 A141633 * A181103 A329487 A220814

Adjacent sequences: A045324 A045325 A045326 * A045328 A045329 A045330

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved