A038056 Number of trees with n 2-colored nodes.

2, 3, 6, 18, 54, 189, 700, 2778, 11486, 49377, 217936, 984818, 4533004, 21198962, 100471862, 481754806, 2333465628, 11404047817, 56177574628, 278710061814, 1391617108600, 6988781174376, 35283390923324, 178990052273558, 912019786448570, 4665994686718118

Offset: 1

Author

Christian G. Bower, Jan 04 1999

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..1000
• Index entries for sequences related to trees

Crossrefs

Cf. A000055, A038055-A038062. Row sums of A294783.

Formula

G.f.: B(x) - B^2(x)/2 + B(x^2)/2, where B(x) is g.f. for A038055.