0,3

ENIPS-transformation is explained in A122204. This automorphism permutes the top-level of a list of even length (1 ... 2n) as (2 4 6 ... 2n-2 2n 2n-1 2n-3 ... 5 3 1) and when applied to a list of odd length (1 .. 2n+1), permutes it as (2 4 6 ... 2n-2 2n 2n+1 2n-1 2n-3 ... 5 3 1). Used to construct A127288.

Index entries for signature-permutations of Catalan automorphisms

(Scheme implementation of this automorphism, destructive, that acts on S-expressions, i.e. list-structures:)

(define (*A127286! s) (cond ((pair? s) (*A127286! (cdr s)) (*A057508! s))) s)

Inverse: A127285. a(n) = A057508(A127288(n)).

Sequence in context: A129605 A057509 A130919 this_sequence A130946 A073284 A057511

Adjacent sequences: A127283 A127284 A127285 this_sequence A127287 A127288 A127289

nonn

Antti Karttunen (His-Firstname.His-Surname(AT)gmail.com), Jan 16 2007