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

0,2

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..1000

Index entries for sequences related to trees

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

Crossrefs

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

Sequence in context: A241278 A100239 A245023 * A257621 A190960 A375959

Adjacent sequences: A038077 A038078 A038079 * A038081 A038082 A038083

Keyword

nonn

Author

Christian G. Bower, Jan 04 1999

Status

approved