A144730 a(n) is the smallest positive integer m such that b * (Product_{k=1..n} a(k)) + 1 is prime, with b = 7.

4, 7, 13, 19, 33, 35, 36, 43, 48, 55, 59, 62, 87, 129, 149, 153, 159, 190, 228, 231, 245, 265, 266, 269, 284, 300, 329, 331, 340, 347, 372, 432, 449, 450, 461, 485, 496, 500, 514, 544, 560, 565, 594, 598, 605, 614, 639, 677, 684, 734, 736, 794, 804, 813, 882

Offset: 1

Author

Artur Jasinski, Sep 19 2008

Keywords

• nonn

Crossrefs

A046966, A046972, A144717, A144718, A144722, A144723, A144724, A144725, A144726, A144727, A144728, A144729, A144731

Programs

Mathematica

k = 7; a = {}; Do[If[PrimeQ[k n + 1], k = k n; AppendTo[a, n]], {n, 1, 3000}]; a (*Artur Jasinski*)

Extensions

Definition corrected by Georg Fischer, Jun 18 2021