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%I #5 Apr 30 2014 01:53:48
%S 0,1,3,2,6,8,7,4,5,15,14,19,20,22,16,21,17,9,10,18,11,12,13,39,41,40,
%T 37,38,52,51,53,55,54,60,61,62,64,43,42,56,57,63,44,58,45,23,24,46,25,
%U 26,27,47,59,48,28,29,49,30,31,32,50,33,34,35,36,113,112,117,118,120
%N Permutation of natural numbers induced by the automorphism robl_car_cdr! acting on the parenthesizations encoded by A014486.
%H A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (Includes the complete Scheme source for computing this sequence)
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%o (Scheme function implementing this automorphism on list-structures:)
%o (define (robl_car_cdr! s) (cond ((not (pair? s))) ((not (pair? (cdr s))) (swap! s)) (else (robl! s) (robl_car_cdr! (car s)) (robl_car_cdr! (cdr s)))) s)
%o (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))
%o (define (swap! s) (let ((ex-car (car s))) (set-car! s (cdr s)) (set-cdr! s ex-car) s))
%Y Inverse permutation: A071659. The car/cdr-flipped conjugate of A071655, i.e. A071660(n) = A057163(A071655(A057163(n))). Cf. also A071657, A071658.
%K nonn
%O 0,3
%A _Antti Karttunen_, May 30 2002
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