A136794 Number of unlabeled marked rooted trees with n nodes.

2, 8, 52, 376, 2998, 25256, 222128, 2013680, 18691522, 176743160, 1696546848, 16488151400, 161919802562, 1604274741608, 16016845623764, 160977882238968, 1627406260427490, 16537733701226936

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 A358031 A368453

Adjacent sequences: A136791 A136792 A136793 * A136795 A136796 A136797

Keyword

nonn

Author

Christian G. Bower, Jan 21 2008

Status

approved