OFFSET
0,3
COMMENTS
It seems that a(A014137(n)) = a(A014137(n)-1)+1 = A006894(n+1) for all n. - Antti Karttunen, Jul 30 2012
LINKS
PROG
(Scheme functions below show the essential idea. For a complete source, see "Alternative Catalan Orderings" OEIS Wiki page.)
(define lexrank->arithrankA061579 (lexrank->arithrank-bijection packA061579))
(define (lexrank->arithrank-bijection packfun) (lambda (n) (rank-bintree (binexp->parenthesization (A014486 n)) packfun)))
(define (rank-bintree bt packfun) (cond ((not (pair? bt)) 0) (else (1+ (packfun (rank-bintree (car bt) packfun) (rank-bintree (cdr bt) packfun))))))
(define (packA061579 x y) (/ (+ (expt (+ x y) 2) (* 3 x) y) 2))
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Antti Karttunen, May 30 2002
STATUS
approved