proposed

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editing

proposed

PermutationsNumber of permutations of [n] avoiding {1243,, 1324,, 2431}.

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editing

editing

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allocated for R. J. Mathar

Permutations of [n] avoiding {1243,1324,2431}.

1, 1, 2, 6, 21, 77, 283, 1032, 3740, 13522, 48930, 177564, 646908, 2367121, 8699706, 32108614, 118975273, 442467434, 1651076429, 6180073782, 23197995681, 87304824502, 329357941951, 1245262325246, 4717865597299, 17908489016748, 68099538024617, 259388123347450, 989533568712759

0,3

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 1 No 210.

C := (1-sqrt(1-4*x))/2/x ;

(1 -6*x +13*x^2 -11*x^3 +4*x^4)/(x^2*(1 -x)^2)*C -(1 -6*x +12*x^2 -8*x^3 +2*x^4)/(x^2*(1 -x)*(1 -2*x)) ;

taylor(%, x=0, 40) ;

gfun[seriestolist](%) ;

allocated

nonn,easy

R. J. Mathar, Nov 09 2017

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editing

allocated for R. J. Mathar

allocated

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