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A070889 Denominator of Sum_{k=1..n} mu(k)/k. 3
1, 2, 6, 6, 30, 15, 105, 105, 105, 210, 2310, 2310, 30030, 15015, 5005, 5005, 85085, 85085, 1616615, 1616615, 4849845, 9699690, 223092870, 223092870, 223092870, 111546435, 111546435, 111546435, 3234846615, 2156564410, 66853496710 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..31.

EXAMPLE

a(6)=15 because 1 - 1/2 - 1/3 - 1/5 + 1/6 = 4/30 = 2/15.

MATHEMATICA

Table[ Denominator[ Sum[ MoebiusMu[k]/k, {k, 1, n}]], {n, 1, 37}]

PROG

PARI: t = 0; v = []; for( n = 1, 30, t = t + mu( n) / n; v = concat( v, denom( t))); v

CROSSREFS

Cf. A070888 (denominator).

Sequence in context: A144361 A163641 A216850 * A072744 A056042 A056040

Adjacent sequences:  A070886 A070887 A070888 * A070890 A070891 A070892

KEYWORD

frac,nonn,easy

AUTHOR

Donald S. McDonald, May 17 2002

EXTENSIONS

Edited by Robert G. Wilson v, Jun 10 2002

STATUS

approved

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Last modified February 17 10:59 EST 2019. Contains 320219 sequences. (Running on oeis4.)