A064903 Semiprimes p1*p2 such that p2 > p1 and p2 mod p1 = 5.

133, 329, 403, 427, 623, 721, 781, 817, 917, 1079, 1211, 1241, 1417, 1507, 1603, 1799, 1819, 1897, 1991, 2077, 2191, 2231, 2681, 2779, 2923, 2959, 2983, 3073, 3107, 3269, 3443, 3563, 3661, 4121, 4151, 4169, 4249, 4411, 4427, 4709, 4739, 4837, 5033

Offset: 1

Author

Patrick De Geest, Oct 13 2001

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A001358 (p2 mod p1 = 0), A064899-A064911.

Programs

Mathematica

sp5Q[n_]:=Module[{f=Transpose[FactorInteger[n]][[1]]},Mod[Last[f], First[ f]] == 5]; Select[Range[5500],PrimeOmega[#]==2&&sp5Q[#]&] (* Harvey P. Dale, Aug 12 2014 *)

Extensions

Name clarified by Sean A. Irvine, Jul 31 2023

Offset changed by Andrew Howroyd, Aug 13 2024