0,3
The number of orbits to which the corresponding automorphism(s) partitions the set of A000108(n) binary trees with n internal nodes.
A. Karttunen, C-program for computing the initial terms of this sequence
a(n) = (A000108(n)+A089408(n))/2
(Scheme) (define (A089402 n) (* (/ 1 2) (+ (A000108 n) (A089408 n))))
Sequence in context: A049959 A006545 A121050 this_sequence A127940 A006796 A006076
Adjacent sequences: A089399 A089400 A089401 this_sequence A089403 A089404 A089405
nonn,easy
Antti Karttunen (His_Firstname.His_Surname(AT)iki.fi), Nov 29 2003
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