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A130371
Signature permutation of a Catalan automorphism: apply *A074685 to the last subtree, if the root degree (A057515(n)) is odd.
4
0, 1, 2, 3, 4, 5, 6, 8, 7, 9, 10, 11, 12, 13, 14, 15, 16, 20, 21, 19, 22, 18, 17, 23, 24, 25, 27, 26, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 55, 54, 47, 57, 58, 59, 51, 52, 53, 61, 62, 56, 63, 48, 49, 60, 64, 50, 46, 45, 65, 66, 67, 68, 69, 70, 71
OFFSET
0,3
PROG
(Destructive Scheme implementation of this automorphism, which acts on S-expressions, i.e. list-structures:)
(define (*A130371! s) (if (odd? (length s)) (*A074685! (car (last-pair s)))) s)
CROSSREFS
Inverse: A130372. a(n) = A130370(A074685(n)) = A074686(A130375(A074685(n))) = A130370(A130375(A130369(n))).
Sequence in context: A030555 A100708 A222252 * A130372 A353825 A353824
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 05 2007
STATUS
approved