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 A213870 #4 Jun 24 2012 12:58:28 %S A213870 1,1,21658,15456538890,84386541996407430,1831976833971352074708780, %T A213870 109898940874611419792791074271620, %U A213870 14506158303190746913523011613729321067580,3612014977093890544877702499165438785779326595871,1520262998870097218529031803141231246364682853428845871416 %N A213870 Number of words w where each letter of the n-ary alphabet occurs 10 times and for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z. %e A213870 a(0) = 1: the empty word. %e A213870 a(1) = 1: aaaaaaaaaa. %e A213870 a(2) = 21658: aaaaaaaaaabbbbbbbbbb, aaaaaaaaababbbbbbbbb, ..., baabababababababaabb, baababababababababab. %Y A213870 Row n=10 of A213275. %K A213870 nonn %O A213870 0,3 %A A213870 _Alois P. Heinz_, Jun 23 2012