A064910 Smallest semiprime p*q such that q >= p and q mod p = n.

4, 6, 15, 65, 77, 133, 91, 319, 209, 341, 299, 481, 493, 799, 527, 1007, 1139, 2449, 703, 3611, 989, 1541, 1643, 3589, 1537, 2407, 2747, 2759, 1829, 3811, 1891, 4633, 2993, 3959, 2627, 4033, 2701, 6157, 3239, 9073, 3569, 5461, 4183, 6439, 5141, 6533

Offset: 0

Author

Patrick De Geest, Oct 13 2001

Keywords

• nonn
• changed

Links

• John Cerkan, Table of n, a(n) for n = 0..10000
• John Cerkan, Python 2.7 program

Crossrefs

Cf. A001358 (p2 mod p1 = 0), A064899-A064909, A064911, A053409, A046413.

Programs

Mathematica

nsp[n_Integer] := nsp[n] = Block[{sp = n + 1}, While[PrimeOmega[sp] != 2, sp++]; sp]; a[n_Integer] := Block[{sp = 4}, While[ fi = FactorInteger@ sp; Mod[fi[[-1, 1]], fi[[1, 1]]] != n, sp = nsp[sp]]; sp]; Array[a, 46, 0] (* Robert G. Wilson v, Aug 20 2025 *)

Extensions

Name amended by John Cerkan, Apr 12 2018