Number of essentially 3-connected rooted toroidal maps with n edges.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =11a(5) =40a(6) =166a(7) =658a(8) =2647a(9) =10592a(10) =42446a(11) =169972a(12) =680670a(13) =2725320a(14) =10910992a(15) =43678882a(16) =174843151a(17) =699839680a(18) =2801078662a(19) =11210671612a(20) =44866276906a(21) =179552951440a(22) =718539964132