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 A293115 #9 Oct 16 2017 10:52:10 %S A293115 1,1,8,53,410,3576,35878,391136,4666521,59096165,797628339, %T A293115 11282268353,167582833398,2587994886476,41585338511800, %U A293115 690912445945576,11870082701946292,209995330141487944,3824511903396303251,71496027436457015058,1371314535020854180410 %N A293115 Number of sets of nonempty words with a total of 2n letters over n-ary alphabet containing the n-th letter such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter. %H A293115 Alois P. Heinz, <a href="/A293115/b293115.txt">Table of n, a(n) for n = 0..26</a> %F A293115 a(n) = A293113(2n,n). %Y A293115 Cf. A182172, A293111, A293113. %K A293115 nonn %O A293115 0,3 %A A293115 _Alois P. Heinz_, Sep 30 2017