A294706 - OEIS

%I #13 Mar 21 2021 21:39:37

%S 1,1,2,6,21,69,162,240,199,73

%N Number of permutations of [n] avoiding {4321, 3412, 1234}.

%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 [math.CO] (2017), Table 2 No 1.

%p p := 73*x^9+199*x^8+240*x^7+162*x^6+69*x^5+21*x^4+6*x^3+2*x^2+x+1 ;

%p taylor(p,x=0,40) ;

%p gfun[seriestolist](%) ;

%K nonn,easy,fini,full

%O 0,3

%A _R. J. Mathar_, Nov 07 2017