Number of rooted planar bi-Eulerian maps with 2n edges. Bi-Eulerian: all its vertices and faces are of even valency.

A069726

Number of rooted planar bi-Eulerian maps with 2n edges. Bi-Eulerian: all its vertices and faces are of even valency.

Terms

    a(0) =1a(1) =1a(2) =6a(3) =54a(4) =594a(5) =7371a(6) =99144a(7) =1412802a(8) =21025818a(9) =323686935a(10) =5120138790a(11) =82812679560

External references