A294702 - OEIS

A294702

Number of permutations of [n] avoiding {1324, 2143, 3412}.

1, 1, 2, 6, 21, 71, 222, 648, 1797, 4807, 12548, 32236, 82009, 207529, 524060, 1323540, 3348087, 8491157, 21600888, 55131630, 141172311, 362617861, 934098062, 2412413026, 6244420411, 16195018711, 42072199862, 109451155098, 285073305417, 743218623827, 1939213856418, 5063148655716

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OFFSET

0,3

LINKS

Table of n, a(n) for n=0..31.

D. Callan, T. Mansour, Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns, arXiv:1705.00933 [math.CO] (2017), Table 1 No 35.

MAPLE

p := 1-9*x+33*x^2-62*x^3+64*x^4-38*x^5+10*x^6 ;

q := (1-3*x+x^2)*(1-2*x)^2*(1-x)^3 ;

taylor(p/q, x=0, 40) ;

gfun[seriestolist](%) ;

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