A055291 Number of trees with n nodes and 4 leaves.

1, 2, 4, 8, 14, 23, 36, 54, 78, 110, 150, 201, 264, 341, 433, 544, 674, 827, 1004, 1209, 1443, 1711, 2013, 2355, 2738, 3167, 3643, 4173, 4757, 5402, 6109, 6885, 7731, 8655, 9657, 10746, 11923, 13196, 14566, 16043, 17627, 19328, 21147, 23094

Offset: 5

Author

Christian G. Bower, May 09 2000

Keywords

• nonn

Links

• Georg Fischer, Table of n, a(n) for n = 5..250
• Index entries for sequences related to trees

Crossrefs

Column 4 of A055290.

Formula

G.f.: x^5(x^5+x^3+1)/[(1-x^3)(1+x^2)(1-x^2)^2(1-x)^2].