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editing
approved
Alois P. Heinz, <a href="/A305839/b305839.txt">Table of n, a(n) for n = 0..400</a>
a
Number of unlabeled forests of rooted trees with 2n edges and n connected components, in which the outdegree of each node is <= 2 and the symmetric group acts on the components.
a(n) = A088326(2n+1,,n+1).
allocated for Alois P. Heinz
a
1, 1, 3, 6, 15, 32, 77, 172, 405, 930, 2180, 5070, 11914, 27929, 65829, 155202, 367053, 868990, 2061723, 4897502, 11652547, 27757960, 66210042, 158103242, 377957299, 904439542, 2166408422, 5193894809, 12463003846, 29929966312, 71933014935, 173009938416
0,3
a(n) = A088326(2n+1,n+1).
Cf. A088326.
allocated
nonn
Alois P. Heinz, Jun 11 2018
approved
editing
allocated for Alois P. Heinz
allocated
approved