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) = (1/3 * A000108(n)) + (2/3 * A089848(n))

A089847 := n -> (1/3)*(A000108(n)+2*A089848(n));

(Scheme) (define (A089847 n) (/ (+ (A000108 n) (* 2 (A089848 n))) 3))

Adjacent sequences: A089844 A089845 A089846 this_sequence A089848 A089849 A089850

Sequence in context: A032096 A120763 A120708 this_sequence A038561 A055981 A120260

nonn,easy

Antti Karttunen (His_Firstname.His_Surname(AT)iki.fi), Nov 29 2003