A004627 Divisible only by primes congruent to 5 mod 8.

1, 5, 13, 25, 29, 37, 53, 61, 65, 101, 109, 125, 145, 149, 157, 169, 173, 181, 185, 197, 229, 265, 269, 277, 293, 305, 317, 325, 349, 373, 377, 389, 397, 421, 461, 481, 505, 509, 541, 545, 557, 613, 625, 653, 661

Offset

1,2

Links

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

Mathematica

ok[1]=True; ok[n_]:=And@@(Mod[#, 8]==5&)/@FactorInteger[n][[All, 1]]; Select[Range[3000], ok] (* Vincenzo Librandi, Aug 20 2012 *)

Prog

(Magma) [n: n in [1..1000] | forall{d: d in PrimeDivisors(n) | d mod 8 eq 5}]; // Vincenzo Librandi, Aug 20 2012

Crossrefs

Sequence in context: A344813 A190618 A309585 * A066782 A094553 A094079

Adjacent sequences: A004624 A004625 A004626 * A004628 A004629 A004630

Keyword

nonn

Author

N. J. A. Sloane

Extensions

Offset changed from 0 to 1 by Vincenzo Librandi, Aug 20 2012

Status

approved