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A080299
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A014486-encoding of plane binary trees (Stanley's d) whose interior zigzag-tree (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).
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5
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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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listen;
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OFFSET
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0,1
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COMMENTS
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These trees are obtained by replacing each non-root terminal node (a leaf) of the binary tree with a branch of two leaves, i.e. . -> \/
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LINKS
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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
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FORMULA
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a(n) = A080310(A014486(n))
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CROSSREFS
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a(n) = A014486(A080298(n)). Breadth-first-wise encoding: A080313.
Sequence in context: A048610 A007511 A016032 * A083939 A083941 A080263
Adjacent sequences: A080296 A080297 A080298 * A080300 A080301 A080302
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KEYWORD
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nonn
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AUTHOR
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Antti Karttunen Mar 02 2003
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STATUS
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approved
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