Average least common multiple
November 24, 2013
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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