Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 4500 articles have referenced us, often saying "we would not have discovered this result without the OEIS".
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