A113053 Beginning with 7, primes of the form: least multiple of the previous term followed by a 1. Beginning with 7, a(n) is the least prime of the form k*a(n-1)*10 +1.

7, 71, 2131, 191791, 5753731, 575373101, 17261193031, 517835790931, 82853726548961, 28998804292136351, 16239330403596356561, 4384619208971016271471, 526154305076521952576521

Offset

1,1

Links

Table of n, a(n) for n=1..13.

Mathematica

nxt[n_]:=Module[{k=1}, While[CompositeQ[10*k*n+1], k++]; 10*k*n+1]; NestList[ nxt, 7, 20] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 04 2019 *)

Crossrefs

Sequence in context: A002119 A146752 A022518 * A218384 A022503 A063861

Adjacent sequences: A113050 A113051 A113052 * A113054 A113055 A113056

Keyword

base,nonn

Author

Amarnath Murthy, Jan 03 2006

Extensions

More terms from Joshua Zucker, Jan 11 2006

Status

approved