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Search: id:A145459
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| 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; listen)
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OFFSET
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0,11
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COMMENT
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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.
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LINKS
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N. J. A. Sloane, Transforms
Index entries for sequences related to rooted trees
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MAPLE
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a:= proc(n) option remember; local j; `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);
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CROSSREFS
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Cf. 9th column of A145460, A143398.
Sequence in context: A023035 A128936 A000582 this_sequence A034241 A022575 A024210
Adjacent sequences: A145456 A145457 A145458 this_sequence A145460 A145461 A145462
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KEYWORD
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nonn
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AUTHOR
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Alois P. Heinz (heinz(AT)hs-heilbronn.de), Oct 10 2008
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