A072532 a(0)=1; for n>0, a(n) = smallest prime of the form k*a(n-1)-1 with k>1.

1, 2, 3, 5, 19, 37, 73, 1021, 8167, 16333, 326659, 3919907, 47038883, 188155531, 2257866371, 76767456613, 1535349132259, 12282793058071, 147393516696851, 4127018467511827, 107302480155307501, 1502234722174305013

Offset

0,2

Comments

Conjecture: If a(n) = k*a(n-1)-1 then k < a(n-1).

A theorem of Dirichlet shows the sequence to be infinite. - Don Reble, Aug 03 2002

Links

T. D. Noe, Table of n, a(n) for n=0..100

Mathematica

f[n_]:=Module[{k=2}, While[!PrimeQ[k*n-1], k++]; k*n-1]; Join[{1}, NestList[ f, 2, 35]] (* Harvey P. Dale, Jun 27 2011 *)

Crossrefs

Cf. A061092.

Sequence in context: A215308 A215104 A174161 * A215373 A359939 A038705

Adjacent sequences: A072529 A072530 A072531 * A072533 A072534 A072535

Keyword

nice,nonn

Author

Amarnath Murthy, Aug 02 2002

Extensions

More terms from Don Reble, Aug 03 2002

Status

approved