Number of unsensed 2-connected planar maps with n edges.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =6a(5) =15a(6) =36a(7) =114a(8) =396a(9) =1565a(10) =6756a(11) =31563a(12) =154370a(13) =785113a(14) =4099948a(15) =21870704a(16) =118624544a(17) =652485364a(18) =3631820462a(19) =20426666644a(20) =115949791342a(21) =663640383400