Array read by antidiagonals: T(n,m) = number of Hamiltonian cycles in C_n X C_m.

Terms

a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1a(5) =1a(6) =1a(7) =3a(8) =3a(9) =1a(10) =1a(11) =6a(12) =48a(13) =6a(14) =1a(15) =1a(16) =5a(17) =126a(18) =126a(19) =5a(20) =1a(21) =1a(22) =8a(23) =390a(24) =1344a(25) =390a(26) =8a(27) =1a(28) =1a(29) =7