Number of sensed simple planar maps with n vertices and 2 faces.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =8a(5) =29a(6) =113a(7) =444a(8) =1763a(9) =6951a(10) =27395a(11) =107672a(12) =422330a(13) =1654180a(14) =6472518a(15) =25308760a(16) =98923442a(17) =386589398a(18) =1510737079a(19) =5904291401a(20) =23079308104a(21) =90236258057a(22) =352908128341