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A127387
Signature-permutation of a Catalan automorphism, a self-inverse variant of A127377.
7
0, 1, 3, 2, 8, 7, 6, 5, 4, 22, 21, 20, 18, 17, 14, 15, 19, 13, 12, 16, 11, 10, 9, 64, 63, 62, 59, 58, 54, 55, 61, 50, 49, 57, 48, 46, 45, 37, 38, 39, 41, 40, 51, 52, 60, 36, 35, 56, 34, 32, 31, 42, 43, 53, 28, 29, 47, 33, 27, 26, 44, 30, 25, 24, 23, 196, 195, 194, 190, 189
OFFSET
0,3
COMMENTS
Used to construct A127388.
PROG
(Scheme implementation of this automorphism, destructive, that acts on S-expressions, i.e. list-structures:)
(define (*A127387! s) (cond ((null? s)) ((null? (car s)) (*A069770! s) (*A127387! (car s))) ((null? (cdr s)) (*A069770! s) (*A127387! (cdr s))) (else (*A127388! s))) s)
CROSSREFS
The number of cycles and the number of fixed points in range [A014137(n-1)..A014138(n-1)] of this involution are given by A127385 and A127389. (This automorphism has the same fixed points as A127377/A127378). A127302(a(n)) = A127302(n) holds for all n.
Sequence in context: A130359 A122340 A082347 * A130360 A082348 A122339
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 16 2007
STATUS
approved