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%I #8 Jun 07 2021 12:00:06
%S 1,1,3,5,11,22,49,104,232,513,1159,2619,5989,13734,31729,73555,171377,
%T 400631,940104,2212542,5222932,12360976,29327260,69735757,166170966,
%U 396727768,948897250,2273409345,5455374972,13110384631,31550978034,76029236983,183437066950
%N Number of rooted identity trees with n nodes and exactly 2 subtrees from the root.
%H Alois P. Heinz, <a href="/A227806/b227806.txt">Table of n, a(n) for n = 4..800</a>
%F a(n) ~ c * d^n / n^(3/2), where d = A246169 = 2.51754035263200389079535459846344... and c = 0.14400421547102520752812171064737721... - _Vaclav Kotesovec_, Jun 07 2021
%e : o : o : o o o :
%e : / \ : / \ : / \ / \ / \ :
%e : o o : o o : o o o o o o :
%e : | : | : | | / \ | :
%e : o : o : o o o o o :
%e : : | : | | | :
%e : : o : o o o :
%e : : : | :
%e : n=4 : n=5 : n=6 o :
%Y Column k=2 of A227774.
%K nonn
%O 4,3
%A _Alois P. Heinz_, Jul 31 2013