Number of loopless rooted planar maps with 3 faces and n vertices and no isthmuses. Also a(n)=T(4,n-3), array T as in A049600.
A006416
Number of loopless rooted planar maps with 3 faces and n vertices and no isthmuses. Also a(n)=T(4,n-3), array T as in A049600.
Terms
- a(0) =1a(1) =8a(2) =20a(3) =38a(4) =63a(5) =96a(6) =138a(7) =190a(8) =253a(9) =328a(10) =416a(11) =518a(12) =635a(13) =768a(14) =918a(15) =1086a(16) =1273a(17) =1480a(18) =1708a(19) =1958a(20) =2231a(21) =2528a(22) =2850a(23) =3198a(24) =3573a(25) =3976a(26) =4408a(27) =4870a(28) =5363a(29) =5888
External references
- oeis: A006416