Triangle read by rows: T(n,k) is number of hex trees with n edges and k leaves (n >= 1, 1 <= k <= 1 + floor(n/2)).
A126177
Triangle read by rows: T(n,k) is number of hex trees with n edges and k leaves (n >= 1, 1 <= k <= 1 + floor(n/2)).
Terms
- a(0) =3a(1) =9a(2) =1a(3) =27a(4) =9a(5) =81a(6) =54a(7) =2a(8) =243a(9) =270a(10) =30a(11) =729a(12) =1215a(13) =270a(14) =5a(15) =2187a(16) =5103a(17) =1890a(18) =105a(19) =6561a(20) =20412a(21) =11340a(22) =1260a(23) =14a(24) =19683a(25) =78732a(26) =61236a(27) =11340a(28) =378a(29) =59049
External references
- oeis: A126177