A139716 If k is the largest divisor of n that is <= sqrt(n) then a(n) = n - k^2.

0, 1, 2, 0, 4, 2, 6, 4, 0, 6, 10, 3, 12, 10, 6, 0, 16, 9, 18, 4, 12, 18, 22, 8, 0, 22, 18, 12, 28, 5, 30, 16, 24, 30, 10, 0, 36, 34, 30, 15, 40, 6, 42, 28, 20, 42, 46, 12, 0, 25, 42, 36, 52, 18, 30, 7, 48, 54, 58, 24, 60, 58, 14, 0, 40, 30, 66, 52, 60, 21, 70, 8, 72, 70, 50, 60, 28, 42