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A245861
Number of preferential arrangements of n labeled elements such that the minimal number of elements per rank equals 8.
2
1, 0, 0, 0, 0, 0, 0, 0, 12870, 48620, 87516, 151164, 251940, 406980, 639540, 980628, 9466982712, 78881427900, 432962644400, 1733914096200, 6029537213700, 19273224716460, 58178097911700, 168431757261300, 100033451495909100, 1461521434059544572
OFFSET
8,9
LINKS
FORMULA
E.g.f.: 1/(1-Sum_{j>=8} x^j/j!) - 1/(1-Sum_{j>=9} x^j/j!).
a(n) = A245793(n) - A245794(n) = A245732(n,8) - A245732(n,9).
MAPLE
b:= proc(n, k) option remember; `if`(n=0, 1,
add(b(n-j, k)*binomial(n, j), j=k..n))
end:
a:= n-> b(n, 8) -b(n, 9):
seq(a(n), n=8..35);
CROSSREFS
Column k=8 of A245733.
Sequence in context: A268851 A024752 A024760 * A068359 A177310 A140917
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Aug 04 2014
STATUS
approved