A116819 - OEIS

%I #10 Mar 31 2023 16:08:41

%S 1,2,6,21,76,274,978,3463,12201,42869,150415,527426,1848905,6480722,

%T 22715293,79617891,279063942,978133274,3428414441,12016810218,

%U 42119714480,147632440224,517461749617,1813738775801,6357278456431

%N Number of permutations of length n which avoid the patterns 2431, 4123, 4231.

%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_04">Index entries for linear recurrences with constant coefficients</a>, signature (7,-16,14,-3).

%F G.f.: A(x) = -{(3x^3-8x^2+5x-1)x}/{3x^4-14x^3+16x^2-7x+1}

%t LinearRecurrence[{7,-16,14,-3},{1,2,6,21},30] (* _Harvey P. Dale_, Mar 31 2023 *)

%K nonn,easy

%O 1,2

%A _Lara Pudwell_, Feb 26 2006