Triangle read by rows: T(n,k) is the number of planar tanglegrams of size n with 0 <= k < n leaf-matched pairs. A leaf matched pair is a pair of non-leaf vertices (u,v) in the tanglegram such that the induced subtrees rooted and u and v also form a tanglegram (equivalently, the leaves in these two subtrees are matched by the matching that forms the original tanglegram).
A349409
Triangle read by rows: T(n,k) is the number of planar tanglegrams of size n with 0 <= k < n leaf-matched pairs. A leaf matched pair is a pair of non-leaf vertices (u,v) in the tanglegram such that the induced subtrees rooted and u and v also form a tanglegram (equivalently, the leaves in these two subtrees are matched by the matching that forms the original tanglegram).
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =0a(7) =5a(8) =4a(9) =2a(10) =0a(11) =34a(12) =28a(13) =11a(14) =3a(15) =0a(16) =273a(17) =239a(18) =102a(19) =29a(20) =6a(21) =0a(22) =2436a(23) =2283a(24) =1045a(25) =325a(26) =73a(27) =11a(28) =0a(29) =23391
External references
- oeis: A349409