OFFSET
0,4
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
FORMULA
For all n >= 0, a(2n+3)/3 = A079444(n).
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Antti Karttunen, Jan 27 2003
EXTENSIONS
Name corrected by Antti Karttunen, Dec 13 2017
STATUS
approved