OFFSET
0,3
COMMENTS
This automorphism reflects over the x-axis the interpretation n (the non-crossing handshakes) of Stanley's exercise 19.
Note that DeepRev (A057164) reflects over y-axis.
LINKS
A. Karttunen, Gatomorphisms (Includes the complete Scheme program for computing this sequence)
R. P. Stanley, Exercises on Catalan and Related Numbers
PROG
(Scheme function implementing this automorphism on list-structures:) (define (xReflectHandshakes a) (DeepRev (RotateHandshakes180 a)))
(define (DeepRev lista) (cond ((not (pair? lista)) lista) ((null? (cdr lista)) (cons (DeepRev (car lista)) (list))) (else (append (DeepRev (cdr lista)) (DeepRev (cons (car lista) (list)))))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 16 2002
STATUS
approved