id:A072095 - OEIS Search Results

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A072095

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

+0
6

0, 1, 3, 2, 7, 6, 8, 4, 5, 17, 16, 18, 15, 14, 20, 19, 21, 9, 10, 22, 11, 12, 13, 45, 44, 46, 42, 43, 48, 47, 49, 40, 39, 50, 41, 37, 38, 54, 53, 55, 52, 51, 57, 56, 58, 23, 24, 59, 25, 26, 27, 61, 60, 62, 28, 29, 63, 30, 31, 32, 64, 33, 34, 35, 36, 129, 128, 130, 127, 126 (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 (cdr_robl_cdr! s) (cond ((not (pair? s))) ((not (pair? (cdr s))) (swap! s)) (else (cdr_robl_cdr! (cdr s)) (robl! s) (cdr_robl_cdr! (cdr s)))) 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	`Inverse permutation: A072094. The car/cdr-flipped conjugate of A072092, i.e. A072095(n) = A057163(A072092(A057163(n))). Cf. also A071655-A071660, A072090-A072091.` `Adjacent sequences: A072092 A072093 A072094 this_sequence A072096 A072097 A072098` `Sequence in context: A071656 A130963 A130930 this_sequence A131009 A129609 A130924`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen Jun 25 2002`

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Last modified October 12 13:44 EDT 2008. Contains 144830 sequences.

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