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 A128156 #7 Oct 02 2013 15:12:55
%S A128156 3,7,13,6,11,10,87,62,209,18,35,122,4083,22,16584420001,17,1343851,34,
%T A128156 453,44,215,26,469,58,69,46,121,36,266461,49,813,56,19499,74,58501,
%U A128156 230,123,218,2077,78,17845,214,579,106,24313642489,90,6541,88,57,206
%N A128156 a(n) = least k such that the remainder when 16^k is divided by k is n.
%H A128156 Robert G. Wilson v, <a href="/A128156/a128156.txt">Table of n, a(n) for n = 1..10000 with -1 for large entries where a(n) has not yet been found</a>
%t A128156 t = Table[0, {10000} ]; k = 1; While[ k < 4100000000, a = PowerMod[16, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t
%Y A128156 Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128154, A128155, A128157, A128158, A128159, A128160, A128149, A128150.
%K A128156 hard,nonn
%O A128156 1,1
%A A128156 _Alexander Adamchuk_, Feb 16 2007
%E A128156 More terms from _Ryan Propper_, Feb 27 2007