

A301934


Number of positive subsetsum trees of weight n.


4




OFFSET

1,2


COMMENTS

A positive subsetsum tree with root x is either the symbol x itself, or is obtained by first choosing a positive subsetsum x <= (y_1,...,y_k) with k > 1 and then choosing a positive subsetsum tree with root y_i for each i = 1...k. The weight is the sum of the leaves. We write positive subsetsum trees in the form rootsum(branch,...,branch). For example, 4(1(1,3),2,2(1,1)) is a positive subsetsum tree with composite 4(1,1,1,2,3) and weight 8.


LINKS

Table of n, a(n) for n=1..9.


EXAMPLE

The a(3) = 14 positive subsetsum trees:
3 3(1,2) 3(1,1,1) 3(1,2(1,1))
2(1,2) 2(1,1,1) 2(1,1(1,1)) 2(1(1,1),1) 2(1,2(1,1))
1(1,2) 1(1,1,1) 1(1,1(1,1)) 1(1(1,1),1) 1(1,2(1,1))


CROSSREFS

Cf. A000108, A000712, A108917, A122768, A262671, A262673, A275972, A276024, A284640, A299701, A301854, A301855, A301856, A301935.
Sequence in context: A111538 A324237 A230218 * A160881 A263187 A213628
Adjacent sequences: A301931 A301932 A301933 * A301935 A301936 A301937


KEYWORD

nonn,more


AUTHOR

Gus Wiseman, Mar 28 2018


STATUS

approved



