113584domain: NAppears in sequencesNumber of tree-rooted toroidal maps with 2 faces and n vertices and without separating loops or isthmuses.at n=5A006434Triangle read by rows: Number of ideals in Partial Brauer Monoid PB_n.at n=33A276773Expansion of g.f.: 1/(Sum_{p odd prime} x^p)^2 (even powers only).at n=42A351317