Triangle read by rows: T(n,k) is the number of rooted toroidal maps with n edges and k faces and without separating cycles or isthmuses, n >= 2, k = 1..n-1.
A343090
Triangle read by rows: T(n,k) is the number of rooted toroidal maps with n edges and k faces and without separating cycles or isthmuses, n >= 2, k = 1..n-1.
Terms
- a(0) =1a(1) =4a(2) =4a(3) =10a(4) =47a(5) =10a(6) =20a(7) =240a(8) =240a(9) =20a(10) =35a(11) =831a(12) =2246a(13) =831a(14) =35a(15) =56a(16) =2282a(17) =12656a(18) =12656a(19) =2282a(20) =56a(21) =84a(22) =5362a(23) =52164a(24) =109075a(25) =52164a(26) =5362a(27) =84a(28) =120a(29) =11256
External references
- oeis: A343090