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 A266737 #13 Apr 15 2016 15:22:57
%S A266737 1,1,20,1680,173891,21347262,2977892253,455912368540,74876841353159,
%T A266737 12990339123973119,2354973430941967605,442587722191655715108,
%U A266737 85717352536181708342445,17029266882947116165470103,3457866959157770598680361537,715559803849259851987691458500
%N A266737 Number of words on {1,1,1,2,2,2,3,3,3,4,4,4,...,n,n,n} avoiding the pattern 1234.
%H A266737 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 A266737 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 A266737 Cf. A014606, A220097, A266734, A266735, A266736-A266741.
%K A266737 nonn
%O A266737 0,3
%A A266737 _N. J. A. Sloane_, Jan 06 2016
%E A266737 More terms from _Alois P. Heinz_, Jan 14 2016