



0, 1, 2, 2, 2, 2, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42
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OFFSET

1,3


LINKS

Kevin Ryde, Table of n, a(n) for n = 1..8192


FORMULA

a(n) = (n  1  (2/3)*(4^e_41)  (1)^e_2*(n  1  2*(4^e_41)))/2 where e_4 = floor(log_4(n)) and e_2 = floor(log_2(n)) = floor(log_4(n^2)).  Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Feb 22 2003
a(n) = n  A079947(n). Let k=A000523(n), then a(n) = A000975(k) if k even, or a(n) = n  A000975(k) if k odd.  Kevin Ryde, Jul 23 2019


PROG

(PARI) a(n) = my(k=logint(n, 2), p=(2<<k)\3); if(bittest(k, 0), np, p); /* Kevin Ryde, Jul 23 2019 */
(MAGMA) [&+[Floor(Log(k)/Log(2)) mod 2:k in [1..n]]:n in [1..75]]; // Marius A. Burtea, Oct 25 2019


CROSSREFS

Cf. A000523, A000975, A030301, A079947.
Sequence in context: A109368 A046774 A029105 * A114968 A079629 A029116
Adjacent sequences: A079951 A079952 A079953 * A079955 A079956 A079957


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Feb 22 2003


STATUS

approved



