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 A088622 #8 Jul 19 2015 01:33:47
%S A088622 11,41,31,41,251,61,71,641,811,101,259374246011,0,131,75295361,151,
%T A088622 40961
%N A088622 Smallest prime obtained as the concatenation of a power of n followed by a 1, or 0 if no such number exists.
%C A088622 a(12) = 0. Subsidiary sequence: n such that 10*n^k +1 is composite for all k >0 (indices of zero entries in this sequence): see A088783.
%C A088622 a(17) is too large to display here. After a(17) the sequence continues: 181, 191, 4001, 211, 1368800680154120519681, 0, 241, 251, 6761, 271, 281, 7072811, 9001, 311, 0, 331, 0, 12251, 466561, 13691, 20851361, 23134411, 401
%t A088622 f[n_] := Block[{k = 1}, While[ !PrimeQ[10*n^k + 1] && k != 1500, k++ ]; If[k == 1500, 0, 10*n^k + 1]]; Table[ f[n], {n, 1, 50}] (* _Robert G. Wilson v_, Oct 25 2003 *)
%Y A088622 Cf. A088623, A088782, A088783.
%K A088622 base,nonn
%O A088622 1,1
%A A088622 _Amarnath Murthy_, Oct 19 2003
%E A088622 Next term is too large to include. - _Ray Chandler_, Oct 23 2003
%E A088622 Extended by _Robert G. Wilson v_, Oct 25 2003