OFFSET
0,3
COMMENTS
LINKS
Rémy Sigrist, Table of n, a(n) for n = 0..6917 (first 197 terms from Indranil Ghosh)
Antti Karttunen, Gatomorphisms (includes the complete Scheme program for computing this sequence).
Antti Karttunen, C program which implements this Catalan bijection.
Indranil Ghosh, Python program for computing the sequence.
Rémy Sigrist, PARI program.
EXAMPLE
a(10)=14 and a(14)=10, A014486[10] = 172 (10101100 in binary), A014486[14] = 202 (11001010 in binary) and these encode the following mountain ranges (and the corresponding rooted plane trees), which are reflections of each other:
...../\___________/\
/\/\/__\_________/__\/\/\
...
...../...........\
..\|/.............\|/
MAPLE
a(n) = CatalanRankGlobal(runcounts2binexp(reverse(binexp2runcounts(A014486[n])))) # i.e., reverse and complement the totally balanced binary sequences
PROG
(Scheme function implementing this automorphism on list-structures:) (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)))))))
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 18 2000
STATUS
approved