A127288 Signature-permutation of a Catalan automorphism: composition of A057508 and A127286.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 28, 30, 33, 24, 29, 26, 31, 32, 27, 34, 35, 36, 37, 39, 38, 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, 65, 70, 67, 72, 75, 79, 81

Offset

0,3

Comments

This automorphism permutes the top-level of a list of even length (1 ... 2n) as (1 3 5 2n-1 ... 2n 2n-2 ... 4 2) and when applied to a list of odd length (1 .. 2n+1), permutes it as (1 3 5 2n-1 2n+1 2n 2n-2 ... 4 2).

Links

Table of n, a(n) for n=0..71.

Index entries for signature-permutations of Catalan automorphisms

Prog

(Scheme implementation of this automorphism, destructive, that acts on S-expressions, i.e. list-structures:)
(define (*A127288! s) (*A057508! (*A127286! s)))

Crossrefs

Inverse: A127287. a(n) = A057508(A127286(n)).

Sequence in context: A330430 A031086 A363038 * A127287 A239088 A162344

Adjacent sequences: A127285 A127286 A127287 * A127289 A127290 A127291

Keyword

nonn

Author

Antti Karttunen, Jan 16 2007

Status

approved