Number of rooted non-separable Eulerian planar maps with n edges.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =6a(6) =19a(7) =64a(8) =230a(9) =865a(10) =3364a(11) =13443a(12) =54938a(13) =228749a(14) =967628a(15) =4149024a(16) =18000758a(17) =78905518a(18) =349037335a(19) =1556494270a(20) =6991433386a(21) =31609302688a(22) =143755711433a(23) =657301771172