A086545 Smallest k such that nk+1 is a prime and and (n-1)/k is non-composite, or 0 if no such number exists.

1, 2, 1, 2, 1, 6, 0, 4, 3, 2, 1, 4, 0, 2, 15, 8, 1, 0, 0, 10, 3, 2, 0, 24, 5, 0, 27, 0, 1, 10, 0, 0, 3, 2, 5, 0, 0, 2, 13, 20, 1, 0, 0, 4, 15, 0, 0, 0, 0, 50, 3, 0, 0, 18, 5, 8, 19, 0, 1, 12, 0, 2, 9, 32, 5, 66, 0, 4, 3, 0, 1, 24, 0, 2, 25, 38, 7, 78, 0, 16, 0, 2, 0, 12, 5, 0, 0, 44, 89, 30, 0, 4, 3, 2