A087371 Smallest k such that 10^k + 2n-1 is a prime >10, or 0 if no such k exists. Index of the smallest power of 10 which when increased by the n-th odd number yields a prime.

1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 2, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 2, 1, 0, 1, 0, 0, 1, 2, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 3, 2, 0, 0, 1, 0, 1, 2, 0, 1, 1, 0, 2, 0, 0, 1, 1, 0, 0, 1, 0, 2, 1, 0, 1, 4, 0, 1, 0, 0, 1, 1, 0, 0, 2, 0, 1, 1, 0, 1, 1, 0, 2, 0, 0, 6, 1, 0, 0, 2, 0