This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A098876 #12 Jul 28 2015 03:41:14
%S A098876 1,2,1,1,1,1,2523,2,2,1,1,2,1,1,1,2,3,6,63,1,50,38,2,1,1,1,79,1,1,3,1,
%T A098876 4,1,2,2,1,6,1,1,1,5,3,1,18,1,1,11,1,1,26,3,10,1,1,4,2,2,4,1,6,1,4,54,
%U A098876 1,10,1,3,1,2,1,1
%N A098876 Least k such that 3*((6*n)^k) - 1 is prime.
%C A098876 a(72) > 3830, and the sequence then continues: 6, 2, 7, 1, 27, 2, 3, 1, 7, 2, 1, 1, 4, 36, 346, 1, 1, 1, 1, 3, 6, 2, 1, 2, 444, ...
%C A098876 a(72) > 10^4. - _Ray Chandler_, Nov 13 2004
%F A098876 a(A138918(n)) = 1. - _Michel Marcus_, Jul 28 2015
%t A098876 f[n_] := Block[{k = 1}, While[ !PrimeQ[3*((6*n)^k) - 1], k++ ]; k]; Table[ f[n], {n, 71}] (* _Robert G. Wilson v_, Oct 21 2004 *)
%Y A098876 Cf. A098877, A138918.
%K A098876 nonn
%O A098876 1,2
%A A098876 _Pierre CAMI_, Oct 13 2004
%E A098876 Corrected and extended by _Robert G. Wilson v_, Oct 22 2004