login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A072635
Inverse permutation to A072634.
6
0, 1, 3, 2, 6, 8, 7, 19, 16, 5, 15, 4, 14, 52, 43, 51, 42, 20, 22, 53, 60, 21, 61, 56, 179, 155, 178, 154, 177, 164, 557, 163, 556, 11, 39, 13, 41, 151, 123, 153, 125, 12, 40, 33, 117, 152, 124, 471, 381, 477, 553, 479, 555, 505, 1797, 507, 1799, 478, 554, 1536
OFFSET
0,3
PROG
(Scheme functions below show the essential idea. For a complete source, follow the "Gatomorphisms" link.)
(define A072635 (arithrank->lexrank-bijection A059905 A059906))
(define (arithrank->lexrank-bijection pr1 pr2) (lambda (n) (CatalanRankGlobal (parenthesization->binexp (unrank-bintree n pr1 pr2)))))
(define (unrank-bintree rank pr1 pr2) (cond ((zero? rank) (list)) (else (cons (unrank-bintree (pr1 (-1+ rank)) pr1 pr2) (unrank-bintree (pr2 (-1+ rank)) pr1 pr2)))))
(define (A059905 n) (if (zero? n) n (+ (modulo n 2) (* 2 (A059905 (floor->exact (/ n 4)))))))
(define (A059906 n) (A059905 (floor->exact (/ n 2))))
CROSSREFS
A072644 gives the size of the corresponding parenthesizations, i.e. A072644(n) = A029837(A014486(A072635(n))+1)/2 [A029837(n+1) gives the binary width of n].
Sequence in context: A131161 A131006 A122362 * A318049 A352877 A210754
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 02 2002
STATUS
approved