A062563 a(n) = Sum_{k=1..n} d(k)* mu(k), where d(k) is the number of divisors function.

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

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

Partial sums of A226177.

Sequence in context: A320298 A021753 A353412 * A091931 A109824 A011399

Adjacent sequences: A062560 A062561 A062562 * A062564 A062565 A062566

Keyword

sign

Author

Jason Earls, Jul 03 2001

Status

approved