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Number of identity trees with 3-colored nodes.
4

%I #18 Dec 26 2020 17:56:55

%S 1,3,3,9,39,189,981,5490,31674,189954,1170126,7382745,47494197,

%T 310712808,2061987642,13855192866,94113385437,645424668666,

%U 4464027720900,31110200069511,218292811705458,1541172223659249

%N Number of identity trees with 3-colored nodes.

%H Vaclav Kotesovec, <a href="/A038080/b038080.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Tra#trees">Index entries for sequences related to trees</a>

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

%F a(n) ~ c * d^n / n^(5/2), where d = 7.969494030514425004826375511986491746399264355846412073489715938... and c = 0.3712461766927875417276388215355520756010680416348018056669... - _Vaclav Kotesovec_, Dec 26 2020

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

%K nonn

%O 0,2

%A _Christian G. Bower_, Jan 04 1999