A116836 - OEIS

%I #13 Nov 05 2025 15:22:05

%S 1,2,6,21,72,233,739,2343,7458,23801,76016,242777,775265,2475513,

%T 7904587,25240597,80598107,257366469,821825201,2624260190,8379812195,

%U 26758495711,85445488885,272845382481,871252605664,2782092566535

%N Number of permutations of length n which avoid the patterns 2341, 4132, 4321.

%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 54.

%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_09">Index entries for linear recurrences with constant coefficients</a>, signature (7,-19,29,-27,16,-10,7,-7,2).

%F G.f.: -(2x^8 -7x^7 +7x^6 -8x^5 +8x^4 -12x^3 +11x^2 -5x +1)*x/(2x^9 -7x^8 +7x^7 -10x^6 +16x^5 -27x^4 +29x^3 -19x^2 +7x-1).

%t LinearRecurrence[{7,-19,29,-27,16,-10,7,-7,2},{1,2,6,21,72,233,739,2343,7458},30] (* _Harvey P. Dale_, May 04 2024 *)

%K nonn,easy

%O 1,2

%A _Lara Pudwell_, Feb 26 2006