%I #7 Mar 31 2012 13:21:12
%S 0,1,2,3,4,7,5,6,8,9,10,17,16,18,11,20,12,14,15,13,19,21,22,23,24,25,
%T 26,27,45,46,44,42,43,48,47,49,50,28,29,54,53,55,30,57,31,37,38,32,39,
%U 40,41,33,61,34,51,52,35,56,58,59,36,60,62,63,64,65,66,67,68,69,70,71
%N Signature permutation of a nonrecursive Catalan automorphism: row 1654249 of table A089840.
%H A. Karttunen, <a href="/A089840/a089840p.txt">Prolog-program which illustrates the construction of this and other similar nonrecursive Catalan automorphisms.</a>
%H <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a>
%o (Scheme function, destructive implementation of this automorphism acting on S-expressions:) (define (*A123498! s) (cond ((null? s) s) ((and (pair? (cdr s)) (pair? (cadr s))) (let ((old-cddr-s (cddr s))) (set-cdr! (cdr s) (cdadr s)) (set-cdr! (cadr s) old-cddr-s)) (*A074679! s)) ((pair? (cdr s)) (*A072796! s)) ((pair? (car s)) (*A072797! s))) s)
%Y Inverse: A123497. Row 1654249 of A089840. Used to construct automorphism *A123502. A074679(n) = A083927(a(A057123(n))).
%K nonn
%O 0,3
%A _Antti Karttunen_, Oct 11 2006