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 A266738 #12 Apr 15 2016 13:19:10
%S A266738 1,1,20,1680,369600,117392909,46121962742,21198300356500,
%T A266738 11003612776114008,6290031043253973544,3887357166155963541538,
%U A266738 2562077915376091538040250,1782153151031487742187453640,1297781266782084301101836538690,983066960483171632842827775906144
%N A266738 Number of words on {1,1,1,2,2,2,3,3,3,4,4,4,...,n,n,n} avoiding the pattern 12345.
%H A266738 Ferenc Balogh, <a href="http://arxiv.org/abs/1505.01389">A generalization of Gessel's generating function to enumerate words with double or triple occurrences in each letter and without increasing subsequences of a given length</a>, preprint arXiv:1505.01389, 2015.
%H A266738 Shalosh B. Ekhad and Doron Zeilberger, <a href="http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/sloane75.html">The Generating Functions Enumerating 12..d-Avoiding Words with r occurrences of each of 1,2, ..., n are D-finite for all d and all r</a>, 2014
%Y A266738 Cf. A014606, A220097, A266734, A266735, A266736-A266741.
%K A266738 nonn
%O A266738 0,3
%A A266738 _N. J. A. Sloane_, Jan 06 2016
%E A266738 More terms from _Alois P. Heinz_, Jan 14 2016