A089389 Sum of the smallest and the largest nontrivial divisor of n or 0 if n is 1 or a prime.

0, 0, 0, 4, 0, 5, 0, 6, 6, 7, 0, 8, 0, 9, 8, 10, 0, 11, 0, 12, 10, 13, 0, 14, 10, 15, 12, 16, 0, 17, 0, 18, 14, 19, 12, 20, 0, 21, 16, 22, 0, 23, 0, 24, 18, 25, 0, 26, 14, 27, 20, 28, 0, 29, 16, 30, 22, 31, 0, 32, 0, 33, 24, 34, 18, 35, 0, 36, 26, 37, 0, 38, 0, 39, 28, 40, 18, 41, 0, 42