A294814 Number of permutations of [n] avoiding {1324, 1342, 3412}.

1, 1, 2, 6, 21, 75, 260, 864, 2756, 8485, 25365, 74021, 211814, 596506, 1658102, 4560087, 12431775, 33648663, 90537656, 242420772, 646489544, 1718347081, 4554820137, 12046252361, 31799943626, 83818097710, 220650496730, 580264098939, 1524688425651, 4003481631675

Offset

0,3

Links

Table of n, a(n) for n=0..29.

D. Callan and T. Mansour, Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns, arXiv:1705.00933 [math.CO] (2017), Table 1 No 158.

Index entries for linear recurrences with constant coefficients, signature (11,-50,121,-167,130,-52,8).

Maple

(1 -10*x +41*x^2 -87*x^3 +101*x^4 -61*x^5 +15*x^6 -x^7)/((1 -x)^2*(1 -2*x)^3*(1 -3*x +x^2)) ;
taylor(%, x=0, 40) ;
gfun[seriestolist](%) ;

Mathematica

LinearRecurrence[{11, -50, 121, -167, 130, -52, 8}, {1, 1, 2, 6, 21, 75, 260, 864}, 30] (* Harvey P. Dale, May 09 2022 *)

Crossrefs

Sequence in context: A294806 A294807 A294771 * A116816 A116742 A116746

Adjacent sequences: A294811 A294812 A294813 * A294815 A294816 A294817

Keyword

nonn,easy

Author

R. J. Mathar, Nov 09 2017

Status

approved