

A144964


Number of groves of degree n.


0




OFFSET

1,2


COMMENTS

Let Y_n be the set of trees of degree n. A nonempty subset of Y_n is called a grove. The set of all groves of degree n is denoted by Y_n. a(n) for n<= 7 given by rightmost column of Table 1, p. 3, of Bruno and Yasaki: The arithmetic of the natural numbers N can be extended to arithmetic operations on planar binary trees. This gives rise to a noncommutative arithmetic theory. In this exposition, we describe this arithmetree, first defined by Loday and investigate prime trees.


LINKS

Table of n, a(n) for n=1..6.
Adriano Bruno, Dan Yasaki, The arithmetic of trees, arXiv:0809.4448 [math.CO]
J.L. Loday, Arithmetree, J. Algebra 258 (2002), no. 1, 275309.


CROSSREFS

Cf. A000108.
Sequence in context: A002707 A283247 A261472 * A168678 A276199 A118913
Adjacent sequences: A144961 A144962 A144963 * A144965 A144966 A144967


KEYWORD

nonn


AUTHOR

Jonathan Vos Post, Sep 27 2008


STATUS

approved



