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 A293887 #4 Oct 18 2017 19:12:05 %S A293887 1,7,49,268,1448,7228,35878,172470,828380,3924415,18627313,87940196, %T A293887 416581962,1971018227,9364427840,44535275966,212749669917, %U A293887 1018545160923,4898593478484,23625691956720,114460931725922,556278543737430,2715406810871312,13298453769286699 %N A293887 Number of sets of nonempty words with a total of n letters over senary alphabet containing the sixth 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 A293887 Alois P. Heinz, <a href="/A293887/b293887.txt">Table of n, a(n) for n = 6..1000</a> %F A293887 a(n) = A293745(n) - A293744(n). %Y A293887 Column k=6 of A293113. %Y A293887 Cf. A293744, A293745. %K A293887 nonn %O A293887 6,2 %A A293887 _Alois P. Heinz_, Oct 18 2017