A094753 Largest k such that (2n-1)/k + 2 as well as (2n-1)k + 2 are prime, or 0 if no such number exists.

1, 3, 1, 0, 9, 1, 0, 15, 1, 0, 21, 0, 5, 3, 1, 0, 33, 1, 0, 39, 1, 0, 45, 0, 0, 1, 0, 11, 57, 1, 0, 7, 1, 0, 1, 1, 0, 25, 7, 0, 81, 0, 17, 3, 0, 0, 0, 1, 0, 99, 1, 0, 105, 1, 0, 111, 0, 23, 117, 0, 0, 123, 1, 0, 1, 0, 0, 15, 1, 0, 0, 13, 5, 147, 1, 0, 3, 1, 0, 53, 1, 0, 15, 0, 0, 171, 0, 5, 1, 1, 0