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A136794 Number of unlabeled marked rooted trees with n nodes. 3
2, 8, 52, 376, 2998, 25256, 222128, 2013680, 18691522, 176743160, 1696546848, 16488151400, 161919802562, 1604274741608, 16016845623764, 160977882238968, 1627406260427490, 16537733701226936 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A marked rooted tree is a rooted tree where each node and edge is marked as + or -.

REFERENCES

F. Bergeron, G. Labelle and P. Leroux, Combinatorial Species and Tree-Like Structures, Cambridge, 1998, p. 293 (4.1.60).

LINKS

Table of n, a(n) for n=1..18.

L. Foissy, Algebraic structures on typed decorated rooted trees, arXiv:1811.07572 (2018)

Index entries for sequences related to rooted trees

FORMULA

a(n) = A136793(n)/2 = A052763(n)*2.

CROSSREFS

Cf. A136795 (tree version), A136796 (labeled version).

Sequence in context: A030518 A123188 A027329 * A125787 A007832 A111088

Adjacent sequences:  A136791 A136792 A136793 * A136795 A136796 A136797

KEYWORD

nonn

AUTHOR

Christian G. Bower, Jan 21 2008

STATUS

approved

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Last modified December 8 04:46 EST 2019. Contains 329853 sequences. (Running on oeis4.)