This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A072093 #5 May 01 2014 02:47:41 %S A072093 0,1,3,2,6,8,7,4,5,14,15,19,20,22,16,21,18,9,10,17,11,12,13,37,38,39, %T A072093 40,41,51,52,53,54,55,60,61,62,64,42,43,56,57,63,47,58,48,23,24,50,25, %U A072093 26,27,44,59,49,28,29,45,30,31,32,46,33,34,35,36,107,108,109,110,111 %N A072093 Permutation of natural numbers induced by the automorphism car_robl_car! acting on the parenthesizations encoded by A014486. %H A072093 A. Karttunen, <a href="http://www.iki.fi/~kartturi/matikka/Nekomorphisms/gatomorf.htm">Gatomorphisms</a> (Includes the complete Scheme program for computing this sequence) %H A072093 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %o A072093 (Scheme function implementing this automorphism on list-structures:) %o A072093 (define (car_robl_car! s) (cond ((not (pair? s))) ((not (pair? (cdr s))) (swap! s)) (else (car_robl_car! (car s)) (robl! s) (car_robl_car! (car s)))) s) %o A072093 (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 A072093 (define (swap! s) (let ((ex-car (car s))) (set-car! s (cdr s)) (set-cdr! s ex-car) s)) %Y A072093 Inverse permutation: A072092. The car/cdr-flipped conjugate of A072094, i.e. A072093(n) = A057163(A072094(A057163(n))). Cf. also A071655-A071660, A072090-A072091. %K A072093 nonn %O A072093 0,3 %A A072093 _Antti Karttunen_, Jun 25 2002