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 A072771 X-projection of the tabular N X N -> N bijection A072764 and Y-projection of its transpose A072766. 13
 0, 0, 1, 0, 0, 1, 2, 3, 0, 0, 0, 0, 0, 1, 1, 2, 4, 5, 3, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 4, 9, 10, 5, 11, 12, 13, 3, 3, 6, 14, 15, 7, 16, 17, 18, 8, 19, 20, 21, 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,7 COMMENTS This corresponds to Lisp/Scheme function 'car' computed with respect to the lexicographical ordering of parenthesizations/planar binary trees (A014486), i.e. with planar binary trees this is equal to extracting the left subtree (from the root), with general parenthesizations equal to taking the first sub-parenthesization of the top-level list and with general plane trees equal to taking the leftmost branch of the tree (at the root). LINKS A. Karttunen, Gatomorphisms (with the complete Scheme source) CROSSREFS Sequence in context: A208150 A045830 A078771 * A292247 A194016 A292256 Adjacent sequences:  A072768 A072769 A072770 * A072772 A072773 A072774 KEYWORD nonn AUTHOR Antti Karttunen, Jun 12 2002 STATUS approved

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Last modified October 20 02:35 EDT 2019. Contains 328244 sequences. (Running on oeis4.)