A163485 Permutation of integers used for constructing A147995 and A163545.

0, 3, 1, 2, 14, 15, 13, 12, 6, 7, 5, 4, 8, 11, 9, 10, 58, 57, 59, 56, 62, 63, 61, 60, 54, 55, 53, 52, 50, 49, 51, 48, 26, 25, 27, 24, 30, 31, 29, 28, 22, 23, 21, 20, 18, 17, 19, 16, 32, 35, 33, 34, 46, 47, 45, 44, 38, 39, 37, 36, 40, 43, 41, 42, 234, 233, 235, 232, 228, 229

Offset

0,2

Links

A. Karttunen, Table of n, a(n) for n = 0..65535

Index entries for sequences that are permutations of the natural numbers

Prog

(MIT Scheme:)
(define (A163485 n) (let* ((i (floor->exact (/ (A000523 n) 2))) (dd (modulo (floor->exact (/ n (expt 4 i))) 4)) (r (if (zero? n) n (modulo n (expt 4 i))))) (cond ((zero? n) n) ((= 0 dd) (A163485 r)) ((= 1 dd) (+ (* 3 (expt 4 i)) (- (expt 4 i) 1 (A163485 (complement-i-oddpos-lsbs (A057300 r) i))))) ((= 2 dd) (+ (expt 4 i) (- (expt 4 i) 1 (A163485 (complement-i-oddpos-lsbs (A057300 r) i))))) (else (+ (* 2 (expt 4 i)) (A163485 r))))))
(define (complement-i-evenpos-lsbs n i) (if (zero? i) n (+ (- 1 (modulo n 2)) (* 2 (complement-i-oddpos-lsbs (floor->exact (/ n 2)) (-1+ i))))))
(define (complement-i-oddpos-lsbs n i) (+ (* 2 (complement-i-evenpos-lsbs (floor->exact (/ n 2)) i)) (modulo n 2)))

Crossrefs

Inverse: A163486. This permutation can be used to construct array A147995 and its transpose A163545. See A163355 for a bit similarly defined recursive permutation.

Sequence in context: A198627 A198654 A198661 * A276011 A126038 A088363

Adjacent sequences: A163482 A163483 A163484 * A163486 A163487 A163488

Keyword

nonn

Author

Antti Karttunen, Aug 01 2009

Status

approved