A144728 a(n) is the smallest positive integer such that b * (Product_{k=1..n} a(k)) + 1 is prime, with a(n) > a(n-1) for n >= 2, and b = 6.

1, 2, 3, 5, 9, 12, 16, 22, 25, 29, 31, 35, 47, 57, 61, 66, 79, 81, 108, 114, 148, 163, 172, 185, 198, 203, 205, 236, 265, 275, 282, 294, 312, 344, 359, 377, 397, 398, 411, 427, 431, 493, 512, 589, 647, 648, 660, 708, 719, 765, 887, 911, 916, 935, 1062, 1093, 1102

Offset: 1

Author

Artur Jasinski, Sep 19 2008

Keywords

• nonn

Crossrefs

Cf. A046966, A046972, A144717, A144718, A144722, A144723, A144724, A144725, A144726, A144727, A144729, A144730, A144731.

Programs

Mathematica

k = 6; a = {}; Do[If[PrimeQ[k n + 1], k = k n; AppendTo[a, n]], {n, 1, 3000}]; a

Extensions

Definition corrected by Georg Fischer, Jun 18 2021