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 A293890 #4 Oct 18 2017 19:04:52 %S A293890 1,10,100,752,5541,36977,243498,1535725,9622087,59096165,362231798, %T A293890 2201156531,13388589925,81219563343,494086167465,3007727300865, %U A293890 18380979656356,112620528644918,693158020152524,4281848080792280,26578705462004141,165681105341062256 %N A293890 Number of sets of nonempty words with a total of n letters over nonary alphabet containing the ninth 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 A293890 Alois P. Heinz, <a href="/A293890/b293890.txt">Table of n, a(n) for n = 9..1000</a> %F A293890 a(n) = A293748(n) - A293747(n). %Y A293890 Column k=9 of A293113. %Y A293890 Cf. A293747, A293748. %K A293890 nonn %O A293890 9,2 %A A293890 _Alois P. Heinz_, Oct 18 2017