Triangle read by rows: T(n,k) (0<=k<=n) is the number of labeled graphs having k blue nodes and n-k green ones and only nodes of different colors can be joined by an edge.
A111636
Triangle read by rows: T(n,k) (0<=k<=n) is the number of labeled graphs having k blue nodes and n-k green ones and only nodes of different colors can be joined by an edge.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =1a(6) =1a(7) =12a(8) =12a(9) =1a(10) =1a(11) =32a(12) =96a(13) =32a(14) =1a(15) =1a(16) =80a(17) =640a(18) =640a(19) =80a(20) =1a(21) =1a(22) =192a(23) =3840a(24) =10240a(25) =3840a(26) =192a(27) =1a(28) =1a(29) =448
External references
- oeis: A111636