A116789 - OEIS

%I #10 Nov 05 2025 15:22:05

%S 1,2,6,21,73,231,650,1668,3987,9030,19628,41333,84915,171087,339408,

%T 665004,1289881,2481422,4741442,9009137,17038193,32096591,60263770,

%U 112832696,210754191,392853778,731013500,1358206773,2520242339

%N Number of permutations of length n which avoid the patterns 1234, 2431, 3241.

%H D. Callan, T. Mansour, <a href="https://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 65.

%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 (5,-8,3,2,1,-2,-1,1).

%F G.f.: A(x) = -{(4x^7+4x^6+11x^5+8x^4+4x^3+4x^2-3x+1)x}/{(x^2-x+1)(x-1)^3(x^3+x^2+x-1)}

%K nonn,easy

%O 1,2

%A _Lara Pudwell_, Feb 26 2006