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Search: id:A038052
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A038052 Number of labeled trees of nonempty sets with n points. (Each node is a set of 1 or more points.) +0
5
1, 1, 2, 7, 42, 376, 4513, 68090, 1238968, 26416729, 646140364, 17837852044, 548713088399, 18612963873492, 690271321314292, 27785827303491579, 1206582732097720126, 56224025231569020724, 2798445211000659147033 (list; graph; listen)
OFFSET

0,3

LINKS

T. D. Noe, Table of n, a(n) for n=0..100

Index entries for sequences related to trees

FORMULA

E.g.f.: B(e^x-1) where B is e.g.f. of A000272.

a(n) = Sum_{k=1..n} Stirling2(n, k)*k^(k-2). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Sep 20 2003

CROSSREFS

Cf. A036250, A048802.

Sequence in context: A122942 A109172 A131682 this_sequence A066383 A007065 A011802

Adjacent sequences: A038049 A038050 A038051 this_sequence A038053 A038054 A038055

KEYWORD

nonn,nice,easy

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Jan 04 1999.

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Last modified September 7 23:08 EDT 2008. Contains 143486 sequences.


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