%I #10 Nov 08 2017 07:48:46
%S 1,2,6,21,73,234,691,1910,5019,12690,31147,74694,175843,407810,934179,
%T 2117958,4759915,10617234,23527867,51839462,113639955,247988802,
%U 538968691,1167065766,2518680283,5419041554,11626611531,24880612230
%N Number of permutations of length n which avoid the patterns 1243, 1342, 4312.
%H D. Callan, T. Mansour, <a href="http://arxiv.org/abs/1705.00933">Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns</a>, arXiv:1705.00933 (2017), Table 2 No 68.
%H Lara Pudwell, <a href="http://faculty.valpo.edu/lpudwell/maple/webbook/bookmain.html">Systematic Studies in Pattern Avoidance</a>, 2005.
%H <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (9,-33,63,-66,36,-8).
%F G.f.: A(x) = {x(3x^6-12x^5+22x^4-30x^3+21x^2-7x+1)}/{(2x-1)^3(x-1)^3}
%F a(n)=2^n*(-99/16+29n/32+3n^2/32)+n^2+4n+6, n>1. [From _R. J. Mathar_, Aug 05 2008]
%K nonn,easy
%O 1,2
%A _Lara Pudwell_, Feb 26 2006