A089873 Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A071665/A071666.

1, 1, 2, 2, 2, 4, 4, 4, 10, 6, 10, 12, 16, 20, 36, 28, 56, 46, 104, 84, 166

Offset

0,3

Comments

The number of n-node binary trees fixed by the corresponding automorphism(s).

Links

Table of n, a(n) for n=0..20.

A. Karttunen, C-program for computing the initial terms of this sequence

Crossrefs

Sequence in context: A112801 A344853 A173862 * A275433 A096323 A282562

Adjacent sequences: A089870 A089871 A089872 * A089874 A089875 A089876

Keyword

nonn

Author

Antti Karttunen, Nov 29 2003

Status

approved