

A080299


A014486encoding of plane binary trees (Stanley's d) whose interior zigzagtree (Stanley's c, i.e., tree obtained by discarding the outermost edges of the binary tree) is isomorphic to a valid plane binary tree (Stanley's d).


5



2, 50, 818, 914, 13106, 13202, 14642, 14738, 15506, 209714, 209810, 211250, 211346, 212114, 234290, 234386, 235826, 235922, 236690, 248114, 248210, 248978, 255122, 3355442, 3355538, 3356978, 3357074, 3357842, 3380018, 3380114, 3381554
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OFFSET

0,1


COMMENTS

These trees are obtained by replacing each nonroot terminal node (a leaf) of the binary tree with a branch of two leaves, i.e., "." > "\/".


LINKS

Table of n, a(n) for n=0..30.
A. Karttunen, Nine initial trees can be found here (The trees with the ordinal numbers 1., 6., 39., 53., 345., 359., 477., 491. and 567.)
R. P. Stanley, Exercises on Catalan and Related Numbers


FORMULA

a(n) = A080310(A014486(n)).


CROSSREFS

a(n) = A014486(A080298(n)). Breadthfirstwise encoding: A080313.
Sequence in context: A048610 A007511 A016032 * A083939 A083941 A080263
Adjacent sequences: A080296 A080297 A080298 * A080300 A080301 A080302


KEYWORD

nonn


AUTHOR

Antti Karttunen, Mar 02 2003


STATUS

approved



