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A062563 Sum_{k=1...n} d(k)* mu(k), where d(k) is the number of divisors function. 1
1, -1, -3, -3, -5, -1, -3, -3, -3, 1, -1, -1, -3, 1, 5, 5, 3, 3, 1, 1, 5, 9, 7, 7, 7, 11, 11, 11, 9, 1, -1, -1, 3, 7, 11, 11, 9, 13, 17, 17, 15, 7, 5, 5, 5, 9, 7, 7, 7, 7, 11, 11, 9, 9, 13, 13, 17, 21, 19, 19, 17, 21, 21, 21, 25, 17, 15, 15, 19, 11, 9, 9, 7, 11, 11, 11, 15, 7, 5, 5, 5, 9, 7, 7, 11, 15, 19, 19, 17, 17, 21, 21, 25, 29, 33, 33, 31 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..97.

FORMULA

Also a(n)=sum(k=1,n,2^omega(k)*mu(k)) - Benoit Cloitre, Jun 13 2007

MATHEMATICA

Accumulate[Table[DivisorSigma[0, n]MoebiusMu[n], {n, 100}]] (* Harvey P. Dale, Aug 15 2016 *)

PROG

(PARI) v=[]; for(n=1, 250, v=concat(v, sum(k=1, n, numdiv(k)*moebius(k)))); v

CROSSREFS

Sequence in context: A067462 A320298 A021753 * A091931 A109824 A011399

Adjacent sequences:  A062560 A062561 A062562 * A062564 A062565 A062566

KEYWORD

sign

AUTHOR

Jason Earls, Jul 03 2001

STATUS

approved

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Last modified June 23 11:02 EDT 2021. Contains 345397 sequences. (Running on oeis4.)