A071658 Permutation of natural numbers induced by the automorphism cdr_robl_car! acting on the parenthesizations encoded by A014486.

0, 1, 3, 2, 8, 6, 7, 4, 5, 20, 19, 22, 14, 15, 21, 16, 17, 9, 10, 18, 11, 12, 13, 64, 53, 55, 51, 52, 54, 60, 62, 37, 38, 61, 39, 40, 41, 57, 56, 63, 42, 43, 58, 44, 45, 23, 24, 46, 25, 26, 27, 59, 47, 48, 28, 29, 49, 30, 31, 32, 50, 33, 34, 35, 36, 162, 191, 192, 154, 155

Offset

0,3

Links

Table of n, a(n) for n=0..69.

A. Karttunen, Gatomorphisms (Includes the complete Scheme source for computing this sequence)

Index entries for sequences that are permutations of the natural numbers

Prog

(Scheme function implementing this automorphism on list-structures:)
(define (cdr_robl_car! s) (cond ((not (pair? s))) ((not (pair? (cdr s))) (swap! s)) (else (cdr_robl_car! (cdr s)) (robl! s) (cdr_robl_car! (car 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: A071657 and also its car/cdr-flipped conjugate, i.e. A071658(n) = A057163(A071657(A057163(n))). Cf. also A071655, A071656, A071659, A071660.

Sequence in context: A098163 A260323 A072112 * A089860 A130960 A130927

Adjacent sequences: A071655 A071656 A071657 * A071659 A071660 A071661

Keyword

nonn

Author

Antti Karttunen, May 30 2002

Status

approved