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A145459 Exponential transform of C(n,9) = A000582. 3
1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 10, 55, 220, 715, 2002, 5005, 11440, 24310, 72930, 1016158, 18643560, 258952330, 2845739820, 26177047270, 209411148144, 1495786618975, 9722602868550, 58373582056075, 329869586346300, 1861266055353705 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,11
COMMENTS
a(n) is the number of ways of placing n labeled balls into indistinguishable boxes, where in each filled box 9 balls are seen at the top.
a(n) is also the number of forests of labeled rooted trees of height at most 1, with n labels, where each root contains 9 labels.
LINKS
N. J. A. Sloane, Transforms
FORMULA
E.g.f.: exp(exp(x)*x^9/9!).
MAPLE
a:= proc(n) option remember; `if`(n=0, 1,
add(binomial(n-1, j-1) *binomial(j, 9) *a(n-j), j=1..n))
end:
seq(a(n), n=0..35);
CROSSREFS
9th column of A145460, A143398.
Sequence in context: A000582 A229890 A243744 * A290893 A034241 A341223
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Oct 10 2008
STATUS
approved

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Last modified March 29 06:34 EDT 2024. Contains 371265 sequences. (Running on oeis4.)