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Average least common multiple

Problem 448

Published on 24 November 2013 at 01:00 am [Server Time]

The function lcm(a,b) denotes the least common multiple of a and b.
Let A(n) be the average of the values of lcm(n,i) for 1≤i≤n.
E.g: A(2)=(2+2)/2=2 and A(10)=(10+10+30+20+10+30+70+40+90+10)/10=32.

Let S(n)=∑A(k) for 1≤k≤n.
S(100)=122726.

Find S(99999999019) mod 999999017.


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