A064908 Semiprimes p1*p2 such that p2 mod p1 = 10, with p2 > p1.

299, 473, 551, 1037, 1199, 1271, 1273, 1313, 1441, 1651, 1739, 1817, 2167, 2279, 2327, 2651, 2771, 2813, 2893, 3193, 3341, 3349, 3377, 3439, 3679, 4103, 4331, 4829, 4883, 5071, 5707, 5977, 6049, 6059, 6239, 6281, 6383, 6523, 6817, 7031, 7037, 7097

Offset: 1

Author

Patrick De Geest, Oct 13 2001

Keywords

• nonn

Links

• John Cerkan, Table of n, a(n) for n = 1..10000

Crossrefs

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

Programs

PARI

isok(n) = my(f = factor(n)); (#f~ == 2) && (vecmax(f[,2]) < 2) && ((f[2,1] % f[1,1]) == 10); \\ Michel Marcus, Apr 16 2018

Python

from sympy import factorint
def is_A064908(n):
    f = factorint(n)
    return (sum([f[i] for i in f]) == 2) and (max(f) % min(f) == 10) # John Cerkan, Apr 14 2018

Extensions

Offset changed by John Cerkan, Apr 12 2018