A116753 - OEIS

%I #9 Nov 08 2017 07:49:39

%S 1,2,6,21,73,236,705,1970,5224,13307,32866,79251,187523,437030,

%T 1005935,2291536,5174458,11596189,25816552,57141641,125822061,

%U 275766912,601872301,1308610526,2835334908,6123666671,13186871710,28319917295

%N Number of permutations of length n which avoid the patterns 2134, 3241, 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 70.

%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_08">Index entries for linear recurrences with constant coefficients</a>, signature (11,-52,138,-225,231,-146,52,-8).

%F G.f.: A(x) = -{x(8x^7-41x^6+84x^5-103x^4+79x^3-36x^2+9x-1)}/{(2x-1)^3(x-1)^5}

%K nonn,easy

%O 1,2

%A _Lara Pudwell_, Feb 26 2006