2 problems

For each positive integer $n$, let $\operatorname{sp}(n)$ and $\operatorname{es}(n)$ denote the numbers of sparse paving and elementary split matroids on $[n]$. Let…

For each positive integer $n$, let $\operatorname{mat}(n)$ and $\operatorname{mat}'(n)$ be the numbers of matroids on $[n]$, respectively counted with labels and up to isomorphism.…