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A123501
Signature permutation of a Catalan automorphism: apply *A123497 at the root, then recurse into the left subtree of the right hand side subtree of a binary tree.
4
0, 1, 2, 3, 4, 6, 7, 5, 8, 9, 10, 14, 16, 19, 17, 18, 12, 11, 13, 20, 15, 21, 22, 23, 24, 25, 26, 27, 37, 38, 42, 44, 47, 51, 53, 56, 60, 45, 46, 48, 49, 50, 31, 34, 30, 28, 29, 35, 33, 32, 36, 54, 55, 40, 39, 41, 57, 43, 58, 59, 61, 52, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71
OFFSET
0,3
PROG
(Scheme function, destructive implementation of this automorphism acting on S-expressions:) (define (*A123501! s) (*A123497! s) (cond ((and (pair? s) (pair? (cdr s))) (*A123501! (cadr s)))) s)
CROSSREFS
Inverse: A123502. A057501(n) = A083927(a(A057123(n))) = A083927(A085159(A057123(n))).
Sequence in context: A143102 A013944 A123497 * A073210 A073196 A086430
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 11 2006
STATUS
approved