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The number of orbits to which the corresponding automorphism(s) partitions the set of A000108(n) binary trees with n internal nodes.
Table of n, a(n) for n=0..20.
A. Karttunen, C-program for computing the initial terms of this sequence
Sequence in context: A036620 A036721 A014267 * A091500 A052329 A199883
Adjacent sequences: A089402 A089403 A089404 * A089406 A089407 A089408
Antti Karttunen, Nov 29 2003