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A072532
a(0)=1; for n>0, a(n) = smallest prime of the form k*a(n-1)-1 with k>1.
5
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
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
KEYWORD
nice,nonn
AUTHOR
Amarnath Murthy, Aug 02 2002
EXTENSIONS
More terms from Don Reble, Aug 03 2002
STATUS
approved