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A082351
Permutation of natural numbers induced by the Catalan bijection gma082351 acting on the parenthesizations encoded by A014486/A063171.
9
0, 1, 2, 3, 4, 5, 8, 6, 7, 9, 10, 11, 12, 13, 19, 20, 21, 14, 15, 22, 16, 17, 18, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 51, 52, 53, 54, 55, 56, 57, 58, 37, 38, 59, 39, 40, 41, 60, 61, 62, 42, 43, 63, 44, 45, 46, 64, 47, 48, 49, 50, 65, 66, 67, 68, 69
OFFSET
0,3
PROG
(Scheme functions implementing this automorphism on list-structures:)
(define (gma082351! s) (cond ((not (pair? s)) s) ((not (pair? (car s))) s) ((not (pair? (cdr s))) (robl! (swap! s))) (else (robl! s))))
(define (robl! s) (let ((ex-car (car s))) (set-car! s (cddr s)) (set-cdr! (cdr s) ex-car) (swap! (cdr s)) (swap! s) s))
(define (swap! s) (let ((ex-car (car s))) (set-car! s (cdr s)) (set-cdr! s ex-car) s))
CROSSREFS
Sequence in context: A063948 A113929 A220394 * A122319 A123714 A089857
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 17 2003
STATUS
approved