Binomial coefficients and the operadic butterfly

Abstract

We prove the conjecture of Laubie on dimensions of components of two operads completing Loday's operadic butterfly diagram. For one of these operads, the dimension of the $n$-th component is equal to $\left(\genfrac{}{}{0ex}{}{2n}{n-1}\right)$ for all $n\ne 3$, and for the other it is equal to $\left(\genfrac{}{}{0ex}{}{2n}{n-1}\right)+1$ for all $n\ge 5$.

arXiv comment14 pages, comments are welcome