Triangle read by rows: T(n,k) (n >= 2, k >= 1) is the number of non-crossing connected graphs on n nodes on a circle such that the distance from a fixed node (root) to the next node is k. Rows are indexed 2,3,4,...; columns are indexed 1,2,3, ... .
A143018
Triangle read by rows: T(n,k) (n >= 2, k >= 1) is the number of non-crossing connected graphs on n nodes on a circle such that the distance from a fixed node (root) to the next node is k. Rows are indexed 2,3,4,...; columns are indexed 1,2,3, ... .
Terms
- a(0) =1a(1) =3a(2) =1a(3) =16a(4) =6a(5) =1a(6) =105a(7) =41a(8) =9a(9) =1a(10) =768a(11) =306a(12) =75a(13) =12a(14) =1a(15) =6006a(16) =2422a(17) =630a(18) =118a(19) =15a(20) =1a(21) =49152a(22) =19980a(23) =5394a(24) =1104a(25) =170a(26) =18a(27) =1a(28) =415701a(29) =169941
External references
- oeis: A143018