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 A201134 #6 Mar 30 2012 18:36:00
%S A201134 1,17,1,1,5,5,55,25,37,1,53,5,53,35,47,31,127,11,1,17,11,59,71,5,155,
%T A201134 23,11,1,13,47,43,71,17,77,53,41,13,277,47,5,143,185,157,371,43,127,
%U A201134 119,61,221,79,131,19,49,241,7,121,11,551,157,335,13,17,13
%N A201134 Least k such that (5^n + k)*5^n - 1 is a prime number.
%t A201134 Table[k = 0; While[!PrimeQ[(5^n + k)*5^n - 1], k++]; k, {n, 85}]
%Y A201134 Cf. A191618, A200921.
%K A201134 nonn
%O A201134 1,2
%A A201134 _Michel Lagneau_, Nov 27 2011