A071651 - OEIS

This site is supported by donations to The OEIS Foundation.

A071651

Permutation of natural numbers induced by reranking plane binary trees given in the standard lexicographic order (A014486) with an "arithmetic global ranking algorithm", using A061579 as the packing bijection N X N -> N.

0, 1, 2, 3, 4, 7, 5, 6, 10, 11, 29, 16, 22, 56, 8, 12, 9, 15, 36, 14, 21, 28, 66, 67, 436, 137, 254, 1597, 37, 79, 46, 121, 667, 106, 232, 407, 2212, 17, 38, 23, 30, 68, 13, 18, 20, 78, 465, 44, 153, 276, 1653, 19, 25, 27, 45, 91, 35, 55, 136, 703, 77, 120, 253, 435, 2278 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	LINKS	`A. Karttunen, Gatomorphisms` `Index entries for sequences that are permutations of the natural numbers`
	PROG	`(Scheme functions below show the essential idea. For a complete source, follow the "Gatomorphisms" link.)` `(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	`Inverse permutation: A071652. Cf. also A014486, A061579, A071653, A071654.` `Sequence in context: A014321 A175343 A072767 * A072658 A099864 A056535` `Adjacent sequences: A071648 A071649 A071650 * A071652 A071653 A071654`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen May 30 2002`

Content is available under The OEIS End-User License Agreement .

Last modified February 13 08:12 EST 2012. Contains 205451 sequences.