|
%I #5 Apr 30 2014 01:53:47
%S 0,1,3,2,7,8,5,4,6,17,18,20,21,22,12,13,10,9,11,15,14,19,16,45,46,48,
%T 49,50,54,55,57,58,59,61,62,63,64,31,32,34,35,36,26,27,24,23,25,29,28,
%U 33,30,40,41,38,37,39,52,51,56,60,43,42,47,44,53,129,130,132,133,134
%N Permutation of natural numbers induced by the automorphism robr_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 (robr_car_cdr! s) (cond ((not (pair? s))) ((not (pair? (car s))) (swap! s)) (else (robr! s) (robr_car_cdr! (car s)) (robr_car_cdr! (cdr s)))) s)
%o (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))
%o (define (swap! s) (let ((ex-car (car s))) (set-car! s (cdr s)) (set-cdr! s ex-car) s))
%Y Inverse permutation: A071656. The car/cdr-flipped conjugate of A071660, i.e. A071655(n) = A057163(A071660(A057163(n))). Cf. also A071657, A071658.
%K nonn
%O 0,3
%A _Antti Karttunen_, May 30 2002
|
