Number of nonseparable planar tree-rooted maps with n edges.

A004304

Number of nonseparable planar tree-rooted maps with n edges.

Terms

    a(0) =1a(1) =2a(2) =2a(3) =6a(4) =28a(5) =160a(6) =1036a(7) =7294a(8) =54548a(9) =426960a(10) =3463304a(11) =28910816a(12) =247104976a(13) =2154192248a(14) =19097610480a(15) =171769942086

External references