%I #13 Mar 17 2017 23:27:17
%S 1,1,70,3199,173860,10203181,631326526,40553993125,2678871322640,
%T 180830423671450,12418980645870820,864996624914197495,
%U 60957211831578399100,4338372535640598835279,311386494956413595138930,22513820432313175983170649,1638226907374445245497453464
%N Number of words on {1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,...,n,n,n,n} avoiding the pattern 123.
%H 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 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
%H Nathaniel Shar, <a href="https://pdfs.semanticscholar.org/98e3/71b675789ed6ec4f9c9cd82e2dee9ca79399.pdf">Experimental methods in permutation patterns and bijective proof</a>, PhD Dissertation, Mathematics Department, Rutgers University, May 2016.
%Y Cf. A220097, A266734, A266735, A266737-A266741.
%K nonn
%O 0,3
%A _N. J. A. Sloane_, Jan 06 2016
%E More terms from _Alois P. Heinz_, Jan 14 2016