cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A089865 Permutation of natural numbers induced by Catalan Automorphism *A089865 acting on the parenthesizations/binary trees encoded by A014486/A063171.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 8, 7, 9, 10, 11, 12, 13, 14, 15, 19, 20, 21, 16, 22, 17, 18, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 51, 52, 53, 54, 55, 56, 57, 58, 59, 42, 43, 60, 61, 62, 44, 63, 45, 46, 47, 64, 48, 49, 50, 65, 66, 67, 68, 69
Offset: 0

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Author

Antti Karttunen, Dec 20 2003

Keywords

Comments

This bijection of binary trees is obtained when we apply bijection *A074679 to the left subtree and keep the right subtree intact.
....B...C.......A...B
.....\./.........\./
..A...x....-->....x...C.................A..().........()..A....
...\./.............\./...................\./....-->....\./.....
....x...D...........x...D.................x...C.........x...C..
.....\./.............\./...................\./...........\./...
......x...............x.....................x.............x....
...............................................................
Compare to A154121.
See "Catalan Automorphisms" OEIS-Wiki page for a detailed explanation how to obtain a given integer sequence from this definition.

Crossrefs

Row 4207 of A089840. Inverse of A089866. a(n) = A069770(A154121(A069770(n))).
Number of cycles: A089844. Number of fixed-points: A005807 (prepended with two 1's). Max. cycle size: A089410. LCM of cycle sizes: A089845 (in each range limited by A014137 and A014138).

Extensions

Further comments and constructive version of Scheme-implementation added by Antti Karttunen, Jun 04 2011