A079442 Number of fixed points in range [A014137(n-1)..A014138(n)] of permutation A071663.

1, 1, 0, 3, 0, 9, 0, 21, 0, 45, 0, 99, 0, 195, 0, 399, 0, 801, 0

Offset: 0

Author

Antti Karttunen, Jan 27 2003

Keywords

• nonn
• more
• hard

Links

• R. Donaghey, Automorphisms on Catalan trees and bracketing, J. Combin. Theory, Series B, 29 (1980), 75-90.
• Antti Karttunen, C-program for counting the initial terms of this sequence
• Antti Karttunen, Illustration of initial terms for trees of sizes n=3..11

Crossrefs

Cf. A057505, A071663, A079438, A079441, A079443, A079444.

Occurs in A073202 as row 176609070820803.

Formula

For all n >= 0, a(2n+3)/3 = A079444(n).

Extensions

Name corrected by Antti Karttunen, Dec 13 2017