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A048802 Number of labeled rooted trees of nonempty sets with n points. (Each node is a set of 1 or more points.) +0
5
1, 3, 16, 133, 1521, 22184, 393681, 8233803, 198342718, 5408091155, 164658043397, 5537255169582, 203840528337291, 8153112960102283, 352079321494938344, 16325961781591781401, 809073412162081974237 (list; graph; listen)
OFFSET

1,2

LINKS

Index entries for sequences related to rooted trees

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 861

FORMULA

E.g.f.: B(e^x-1) where B is e.g.f. of A000169.

a(n) = Sum_{k=1..n} Stirling2(n, k)*k^(k-1). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Sep 17 2003

CROSSREFS

Cf. A036249, A038052.

Cf. A058863, A052807.

Sequence in context: A121673 A051921 A023998 this_sequence A119392 A129043 A135746

Adjacent sequences: A048799 A048800 A048801 this_sequence A048803 A048804 A048805

KEYWORD

nonn

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Mar 15 1999.

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Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.


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