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Problem 379


Problem 379


Least common multiple count

Let f(n) be the number of couples (x,y) with x and y positive integers, x ≤ y and the least common multiple of x and y equal to n.

Let g be the summatory function of f, i.e.: g(n) = ∑ f(i) for 1 ≤ i ≤ n.

You are given that g(106) = 37429395.

Find g(1012).


最小公倍数计数

数对(x,y)满足x和y均为正整数,x ≤ y,以及x和y的最小公倍数等于n;记这类数对的数目为f(n)。

记g是f的求和函数,也就是说:g(n) = ∑ f(i),其中1 ≤ i ≤ n。

已知g(106) = 37429395。

求g(1012)。