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 A128367 #9 Aug 01 2015 04:50:59
%S A128367 2,5,6,23,11,7,25,19,10,17,718,165,35,533,33,3738251,178,57,142,9779,
%T A128367 60,2227273193,55,19659,724,17678421233,29,17473,70,19653,209,3005,48,
%U A128367 28777,694,111,346,1441,46,15977,86,3399,12614,4387,116,527
%N A128367 a(n) = least k such that the remainder when 27^k is divided by k is n.
%H A128367 Robert G. Wilson v, <a href="/A128367/a128367.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 A128367 t = Table[0, {10000} ]; k = 1; While[ k < 4500000000, a = PowerMod[27, k, k]; If[a < 10001 && t[[a]] == 0, t[[a]] = k; Print[{a, k}]]; k++ ]; t (* _Robert G. Wilson v_, Aug 06 2009 *)
%Y A128367 Cf. A128361, A128362, A128363, A128364, A128365, A128366, A128368, A128369, A129370, A128371, A128372.
%Y A128367 Cf. A036236, A078457, A119678, A119679, A127816, A119715, A119714, A127817, A127818, A127819, A127820, A127821, A128154, A128155, A128156, A128157, A128158, A128159, A128160.
%Y A128367 Cf. A128149, A128150, A128172.
%K A128367 hard,nonn
%O A128367 1,1
%A A128367 _Alexander Adamchuk_, Feb 27 2007
%E A128367 a(16) - a(25) from _Robert G. Wilson v_, Aug 06 2009