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A264496

Number of permutations of [n] with exactly nine (possibly overlapping) occurrences of the generalized pattern 13-2.

1, 256, 11115, 258564, 4235959, 55145400, 609428105, 5954337792, 52838734860, 433992926048, 3345094317796, 24447556164496, 170782982829160, 1147577406468288, 7455096381483206, 47017233051466444, 288854847620573814, 1733658007070671968, 10189610103251200265

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OFFSET

7,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 7..500

MAPLE

b:= proc(u, o) option remember; `if`(u+o=0, 1, add(

b(u-j, o+j-1), j=1..u) +add(convert(series(

b(u+j-1, o-j)*x^(j-1), x, 10), polynom), j=1..o))

end:

a:= n-> coeff(b(n, 0), x, 9):

seq(a(n), n=7..25);