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 A240610 #11 Aug 28 2014 08:19:24
%S A240610 1,1,2,5,14,45,149,509,1756,6082,21246,74125,260940,917060,3251573,
%T A240610 11514563,41115372,146687475,527318119,1894548198,6853413645,
%U A240610 24782205276,90165044683,327958242274,1199475359682,4386106532923,16118279172044,59223681674225
%N A240610 Number of n-length words w over a 4-ary alphabet such that w is empty or a prefix z concatenated with letter a_i and i=1 or 0 < #(z,a_{i-1}) >= #(z,a_i), where #(z,a_i) counts the occurrences of the i-th letter in z.
%H A240610 Alois P. Heinz and Vaclav Kotesovec, <a href="/A240610/b240610.txt">Table of n, a(n) for n = 0..1000</a> (first 175 terms from Alois P. Heinz)
%H A240610 Vaclav Kotesovec, <a href="/A240610/a240610.txt">Recurrence (of order 6)</a>
%F A240610 a(n) ~ 8465 * 4^n / (18 * Pi * n^3). - _Vaclav Kotesovec_, Aug 28 2014
%Y A240610 Column k=4 of A240608.
%K A240610 nonn
%O A240610 0,3
%A A240610 _Alois P. Heinz_, Apr 09 2014