

A071570


a(n) = 2*sum(d dividing n, 2^mu(d)).


1



4, 5, 5, 7, 5, 10, 5, 9, 7, 10, 5, 14, 5, 10, 10, 11, 5, 14, 5, 14, 10, 10, 5, 18, 7, 10, 9, 14, 5, 20, 5, 13, 10, 10, 10, 20, 5, 10, 10, 18, 5, 20, 5, 14, 14, 10, 5, 22, 7, 14, 10, 14, 5, 18, 10, 18, 10, 10, 5, 28, 5, 10, 14, 15, 10, 20, 5, 14, 10, 20, 5, 26, 5, 10, 14, 14, 10, 20, 5
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OFFSET

1,1


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000


FORMULA

Asymptotically: sum(k=1, n, a(k)) = 2C*n*log(n)+0(n*log(n)) with C=1.1...


PROG

(PARI) for(n=1, 100, print1(2*sumdiv(n, d, 2^moebius(d)), ", "))


CROSSREFS

Sequence in context: A316150 A110883 A178131 * A336047 A082448 A190796
Adjacent sequences: A071567 A071568 A071569 * A071571 A071572 A071573


KEYWORD

easy,nonn


AUTHOR

Benoit Cloitre, May 31 2002


STATUS

approved



