Number of nonseparable tree-rooted planar maps with n + 3 edges and 4 vertices.

Terms

a(0) =4a(1) =75a(2) =604a(3) =3150a(4) =12480a(5) =40788a(6) =115500a(7) =292578a(8) =677820a(9) =1459315a(10) =2954952a(11) =5679700a(12) =10438272a(13) =18449760a(14) =31511880a(15) =52213596a(16) =84206100a(17) =132543411a(18) =204105220a(19) =308116050a(20) =456776320a(21) =666022500a(22) =956435220a(23) =1354315950a(24) =1892954700a(25) =2614113099a(26) =3569749200a(27) =4824012424