A118664 Least prime p such that n*(p#^2)-1 is prime or 0 if n is a square so no prime possible.

2, 2, 2, 0, 2, 2, 3, 2, 0, 3, 2, 2, 3, 3, 2, 0, 2, 2, 3, 2, 2, 269, 3, 3, 0, 2, 2, 7, 5, 29, 11, 2, 2, 3, 2, 0, 11, 2, 5, 3, 2, 2, 5, 3, 2, 5, 5, 2, 0, 2, 17, 3, 2, 11, 3, 2, 2, 3, 7, 2, 7, 5, 2, 0, 3, 2, 3, 2, 5, 7, 2, 3, 5, 3, 3, 5, 2, 2, 3, 3, 0, 41, 2, 3, 7, 7, 2, 3, 3, 2, 5, 2, 3, 53, 2, 2, 3, 3, 7, 0