0,3

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

(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))

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

nonn

Antti Karttunen, May 30 2002

approved