0,3

This is a self-inverse automorfism (an involution). Can be used to construct A130373.

A. Karttunen, Table of n, a(n) for n = 0..2055

Index entries for signature-permutations of Catalan automorphisms

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

(define (*A130340! s) (if (even? (length s)) (*A072796! s)) s)

Cf. a(n) = A057508(A130339(A057508(n))) = A057164(A130339(A057164(n))). a(n) = A072796(n), if A057515(n) mod 2 = 0, otherwise a(n)=n.

Sequence in context: A222245 A275582 A129607 * A130339 A058812 A320454

Adjacent sequences: A130337 A130338 A130339 * A130341 A130342 A130343

nonn

Antti Karttunen, Jun 05 2007

approved