id:A071653 - OEIS Search Results

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Permutation of natural numbers induced by reranking plane binary trees given in the standard lexicographic order (A014486) with an "arithmetic global ranking algorithm", using A001477 as the packing bijection N X N -> N.

+0
4

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

	OFFSET	`0,3`
	LINKS	`A. Karttunen, Gatomorphisms` `Index entries for sequences that are permutations of the natural numbers`
	PROGRAM	`(Scheme functions below show the essential idea. For a complete source, follow the "Gatomorphisms" link.)` `(define lexrank->arithrankA001477 (lexrank->arithrank-bijection packA001477))` `(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 (packA001477 x y) (/ (+ (expt (+ x y) 2) x (* 3 y)) 2))`
	CROSSREFS	`Inverse permutation: A071654. Cf. also A014486, A001477, A071651, A071652.` `Sequence in context: A090780 A063549 A057977 this_sequence A056861 A103245 A019242` `Adjacent sequences: A071650 A071651 A071652 this_sequence A071654 A071655 A071656`
	KEYWORD	`nonn`
	AUTHOR	`Antti Karttunen May 30 2002`

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.

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