A052253 Triangle T(n,k) (n >= 1, k >= 1) giving filtration of bigrading of Hopf algebra of rooted trees.

1, 1, 1, 2, 1, 1, 3, 3, 2, 1, 8, 5, 4, 2, 1, 16, 13, 9, 6, 3, 1, 41, 28, 21, 13, 8, 3, 1, 98, 71, 49, 33, 20, 10, 4, 1, 250, 174, 121, 79, 50, 27, 13, 4, 1, 631, 445, 304, 201, 127, 74, 38, 16, 5, 1, 1646, 1137, 776, 510, 325, 192, 106, 49, 19, 5, 1, 4285, 2974

Offset: 0

Author

David Broadhurst, Feb 05 2000

Keywords

• nonn
• nice
• tabl

Examples

			1; 1,1; 2,1,1; 3,3,2,1; 8,5,4,2,1; ...
		

Links

• D. J. Broadhurst and D. Kreimer, Towards cohomology of renormalization...

Crossrefs

Cf. A052250.