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A072650
Starting from the right (the least significant end) rewrite 0 to 0 and x1 to 1 in the binary expansion of n.
3
0, 1, 2, 1, 4, 3, 2, 3, 8, 5, 6, 5, 4, 3, 6, 3, 16, 9, 10, 9, 12, 7, 10, 7, 8, 5, 6, 5, 12, 7, 6, 7, 32, 17, 18, 17, 20, 11, 18, 11, 24, 13, 14, 13, 20, 11, 14, 11, 16, 9, 10, 9, 12, 7, 10, 7, 24, 13, 14, 13, 12, 7, 14, 7, 64, 33, 34, 33, 36, 19, 34, 19, 40, 21, 22, 21, 36, 19, 22, 19
OFFSET
0,3
FORMULA
A048679(n) = a(A003714(n)).
EXAMPLE
I.e. 23 is 10111 in binary, which after rewriting is 111, thus a(23) = 7, while 38 is 100110 in binary, which after the rewriting is 10010, i.e. a(38) = 18.
PROG
(MIT/GNU Scheme) (define (A072650 n) (let loop ((n n) (s 0) (i 0)) (cond ((zero? n) s) ((even? n) (loop (floor->exact (/ n 2)) s (1+ i))) (else (loop (floor->exact (/ n 4)) (+ s (expt 2 i)) (1+ i))))))
CROSSREFS
Sequence in context: A106407 A023141 A283324 * A082497 A242364 A065620
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 02 2002
STATUS
approved