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A239432
Number of permutations of length n with longest increasing subsequence of length 8.
2
1, 64, 2521, 79861, 2250887, 59367101, 1508071384, 37558353900, 927716186325, 22904111472825, 568209449266202, 14216730315766814, 359666061054003144, 9216708503647774264, 239524408949706575548, 6317740398995612513164, 169207499997274346326579, 4602911809939402715164066
OFFSET
8,2
COMMENTS
In general, for column k of A047874 is a(n) ~ product(j!, j=0..k-1) * k^(2*n+k^2/2) / (2^((k-1)*(k+2)/2) * Pi^((k-1)/2) * n^((k^2-1)/2)) [Regev, 1981].
LINKS
FORMULA
a(n) ~ 1913625 * 2^(6*n+77) / (Pi^(7/2) * n^(63/2)).
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Mar 18 2014
STATUS
approved