id:A072092 - OEIS Search Results

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A072092

Permutation of natural numbers induced by the automorphism car_robr_car! acting on the parenthesizations encoded by A014486.

+0
6

0, 1, 3, 2, 7, 8, 4, 6, 5, 17, 18, 20, 21, 22, 9, 10, 14, 19, 16, 11, 12, 15, 13, 45, 46, 48, 49, 50, 54, 55, 57, 58, 59, 61, 62, 63, 64, 23, 24, 25, 26, 27, 37, 38, 51, 56, 60, 42, 44, 53, 47, 28, 29, 30, 31, 32, 39, 40, 43, 52, 33, 34, 35, 41, 36, 129, 130, 132, 133, 134 (list; graph; listen)

	OFFSET	`0,3`
	LINKS	`A. Karttunen, Gatomorphisms (Includes the complete Scheme program for computing this sequence)` `Index entries for sequences that are permutations of the natural numbers`
	PROGRAM	`(Scheme function implementing this automorphism on list-structures:)` `(define (car_robr_car! s) (cond ((not (pair? s))) ((not (pair? (car s))) (swap! s)) (else (car_robr_car! (car s)) (robr! s) (car_robr_car! (car s)))) s)` `(define (robr! s) (let ((ex-cdr (cdr s))) (set-cdr! s (caar s)) (set-car! (car s) ex-cdr) (swap! (car s)) (swap! s) s))` `(define (swap! s) (let ((ex-car (car s))) (set-car! s (cdr s)) (set-cdr! s ex-car) s))`
	CROSSREFS	`Inverse permutation: A072093. The car/cdr-flipped conjugate of A072095, i.e. A072092(n) = A057163(A072095(A057163(n))). Cf. also A071655-A071660, A072090-A072091.` `Sequence in context: A130926 A069774 A089861 this_sequence A071659 A130931 A130962` `Adjacent sequences: A072089 A072090 A072091 this_sequence A072093 A072094 A072095`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen Jun 25 2002`

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.

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