Fertility fibres and coproduct coefficients in the LOT Hopf algebra

Zhicheng Zhu, Jingtao Li, Xing Gao

We study fibres of the fertility map $\Phi$ from decorated rooted trees to decorated multi-index monomials. For a multi-index $\mathbf{k}$ of weight $-1$, the fibre $\mathcal F_{\math…