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Search: id:A108523
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A108523 Number of rooted identity trees with n generators. +0
1
1, 1, 2, 4, 10, 27, 77, 226, 685, 2112, 6618, 20996, 67337, 217884, 710571, 2332958, 7705429, 25584035, 85346018, 285908169, 961440343, 3244259406, 10981797187, 37280278698, 126890974820, 432950169885, 1480542159038, 5073504809660 (list; graph; listen)
OFFSET

1,3

COMMENT

A generator is a leaf or a node with just one child.

LINKS

N. J. A. Sloane, Transforms

Index entries for sequences related to rooted trees

FORMULA

G.f. satisfies (2-x)*A(x) = x - 1 + WEIGH(A(x))

CROSSREFS

Cf. A108521-A108529, A004111.

Sequence in context: A113066 A002459 A104383 this_sequence A114507 A127386 A099950

Adjacent sequences: A108520 A108521 A108522 this_sequence A108524 A108525 A108526

KEYWORD

nonn

AUTHOR

Christian G. Bower (bowerc(AT)usa.net), Jun 07 2005

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Last modified July 26 23:19 EDT 2008. Contains 142293 sequences.


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