English

A Combinatorial Interpretation for Sequence A345973 in OEIS

Combinatorics 2021-08-12 v1

Abstract

We give a combinatorial interpretation in terms of bicolored ordered trees for the sequence (a_n)_{n>=1}=(1, 1, 1, 2, 3, 6, 10, 20, 36, 73,... ), A345973 in OEIS, whose generating function satisfies the defining identity Sum_{n>=1}a_n x^n = x + x^2/Product_{n>=1}(1 - a_n x^n).

Cite

@article{arxiv.2108.04969,
  title  = {A Combinatorial Interpretation for Sequence A345973 in OEIS},
  author = {David Callan},
  journal= {arXiv preprint arXiv:2108.04969},
  year   = {2021}
}

Comments

3 pages, 1 figure

R2 v1 2026-06-24T05:00:38.935Z