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 A130376 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. 4
 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, 32, 34, 24, 23, 25, 26, 27, 28, 29, 30, 33, 38, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 106, 105, 100, 101, 104 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS A. Karttunen, Table of n, a(n) for n = 0..2055 PROG (Destructive Scheme implementation of this automorphism, which acts on S-expressions, i.e. list-structures:) (define *A130376! (!APPLY-AFTER-FIRST-NIL *A074686!)) (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!)) CROSSREFS Inverse: A130375. a(n) = A130369(A074686(n)) = A074685(A130372(A074686(n))) = A130369(A130372(A130370(n))). Sequence in context: A130341 A130944 A122341 * A130342 A130943 A122342 Adjacent sequences:  A130373 A130374 A130375 * A130377 A130378 A130379 KEYWORD nonn AUTHOR Antti Karttunen, Jun 05 2007 STATUS approved

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