|
%I #5 Mar 31 2012 13:21:14
%S 0,1,2,3,5,4,6,7,8,13,12,9,10,11,14,15,16,17,18,19,20,21,22,36,35,31,
%T 32,34,24,23,25,26,27,28,29,30,33,38,37,39,40,41,42,43,44,45,46,47,48,
%U 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,106,105,100,101,104
%N Signature permutation of a Catalan automorphism: apply *A074686 after the first nil on the top-level of list, if any present, otherwise leave the structure intact.
%H A. Karttunen, <a href="/A130376/b130376.txt">Table of n, a(n) for n = 0..2055</a>
%H <a href="/index/Per#IntegerPermutationCatAuto">Index entries for signature-permutations of Catalan automorphisms</a>
%o (Destructive Scheme implementation of this automorphism, which acts on S-expressions, i.e. list-structures:)
%o (define *A130376! (!APPLY-AFTER-FIRST-NIL *A074686!))
%o (define (!APPLY-AFTER-FIRST-NIL f!) (letrec ((g! (lambda (s) (cond ((pair? s) (if (pair? (car s)) (g! (cdr s)) (f! (cdr s))))) s))) g!))
%Y Inverse: A130375. a(n) = A130369(A074686(n)) = A074685(A130372(A074686(n))) = A130369(A130372(A130370(n))).
%K nonn
%O 0,3
%A _Antti Karttunen_, Jun 05 2007
|
