
Problem 372
18 February 2012
Let R(M, N) be the number of lattice points (x, y) which satisfy M
x
N, M
y
N and
is odd.
We can verify that R(0, 100) = 3019 and R(100, 10000) = 29750422.
Find R(2·106, 109).
Note:
represents the floor function.