A038080 Number of identity trees with 3-colored nodes.

1, 3, 3, 9, 39, 189, 981, 5490, 31674, 189954, 1170126, 7382745, 47494197, 310712808, 2061987642, 13855192866, 94113385437, 645424668666, 4464027720900, 31110200069511, 218292811705458, 1541172223659249

Offset: 0

Author

Christian G. Bower, Jan 04 1999

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..1000
• Index entries for sequences related to trees

Crossrefs

Cf. A000220, A038077-A038079, A052757, A255517.

Formula

G.f.: B(x) - B^2(x)/2 - B(x^2)/2, where B(x) is g.f. for A038079.

a(n) ~ c * d^n / n^(5/2), where d = 7.969494030514425004826375511986491746399264355846412073489715938... and c = 0.3712461766927875417276388215355520756010680416348018056669... - Vaclav Kotesovec, Dec 26 2020