A070891 Denominator of Sum_{k=1..n} mu(k)/k when it changes sign.

30, 15, 105, 210, 2310, 5005, 1616615, 9699690, 223092870, 111546435, 2156564410, 100280245065, 3710369067405, 7420738134810, 6541380665835015

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Prog

(PARI) t = 0; v = []; for( n = 1, 80, t1 = t; t = t + moebius( n) / n; if( t * t1 < 0, v = concat( v, denominator( t)), )); v

Crossrefs

Cf. A070890, A070888, A070889.

Sequence in context: A070657 A089332 A040873 * A033971 A193220 A040872

Adjacent sequences: A070888 A070889 A070890 * A070892 A070893 A070894

Keyword

nonn,frac

Author

Donald S. McDonald, May 17 2002

Status

approved