

A130401


Signature permutations of REDRONItransformations of nonrecursive Catalan automorphisms in table A089840.


17



0, 1, 0, 2, 1, 0, 3, 3, 1, 0, 4, 2, 2, 1, 0, 5, 7, 3, 2, 1, 0, 6, 8, 4, 3, 2, 1, 0, 7, 6, 6, 5, 3, 2, 1, 0, 8, 4, 5, 4, 5, 3, 2, 1, 0, 9, 5, 7, 6, 6, 6, 3, 2, 1, 0, 10, 17, 8, 7, 4, 5, 6, 3, 2, 1, 0, 11, 18, 9, 8, 7, 4, 4, 4, 3, 2, 1, 0, 12, 20, 14, 13, 8, 7, 5, 5, 4, 3, 2, 1, 0, 13, 21, 10, 12, 13
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OFFSET

0,4


COMMENTS

Row n is the signature permutation of the Catalan automorphism which is obtained from the nth nonrecursive automorphism in the table A089840 with the recursion scheme "REDRONI". In this recursion scheme the given automorphism is applied at the root of binary tree after the algorithm has recursed down the cdrbranch (the right hand side tree in the context of binary trees), but before the algorithm recurses down to the carbranch (the left hand side of the binary tree, with respect to the new orientation of branches, possibly changed by the applied automorphism). I.e. this corresponds to the reversed depthfirst inorder traversal of a Catalan structure, when it is interpreted as a binary tree. The associated Schemeprocedures REDRONI and !REDRONI can be used to obtain such a transformed automorphism from any constructively (or respectively: destructively) implemented automorphism. Each row occurs only once in this table and similar notes as given e.g. for table A122202 apply here, e.g. the rows of A089840 all occur here as well. This transformation has many fixed points besides the trivial identity automorphism *A001477: at least *A069770, *A089859 and *A129604 stay as they are. Inverses of these permutations can be found in table A130400.


LINKS

Table of n, a(n) for n=0..95.


PROG

(MIT Scheme:) (define (REDRONI f) (letrec ((g (lambda (s) (foldright (lambda (x y) (let ((t (f (cons x y)))) (cons (g (car t)) (cdr t)))) '() s)))) g))
(define (!REDRONI f!) (letrec ((g! (lambda (s) (cond ((pair? s) (g! (cdr s)) (f! s) (g! (car s)))) s))) g!))


CROSSREFS

Cf. The first 22 rows of this table: row 0 (identity permutation): A001477, 1: A069770, 2: A073285, 3: A122342, 4: A130386, 5: A130384, 6: A130382, 7: A122349, 8: A082342, 9: A130392, 10: A130390, 11: A130388, 12: A071658, 13: A130930, 14: A130932, 15: A089859, 16: A130934, 18: A130394, 19: A130396, 20: A130928, 21: A130398. Other rows: row 1654694: A073280, row 1654720: A129604.
Cf. also tables A089840, A122201A122204, A130402A130403.
Cf. As a sequence differs from A130400 for the first time at n=80, where a(n)=14, while A130401(n)=11.
Sequence in context: A130402 A089840 A130400 * A122289 A122290 A122284
Adjacent sequences: A130398 A130399 A130400 * A130402 A130403 A130404


KEYWORD

nonn,tabl


AUTHOR

Antti Karttunen, Jun 11 2007


STATUS

approved



