A088640 Smallest number suffixed to concatenation of n times n gives a prime.

1, 3, 1, 9, 7, 29, 1, 3, 7, 39, 1, 23, 1, 97, 1, 91, 37, 59, 9, 93, 19, 97, 61, 293, 61, 3, 1, 57, 7, 43, 61, 7, 53, 31, 127, 353, 67, 841, 187, 9, 3, 179, 429, 127, 97, 3, 319, 11, 51, 39, 191, 33, 3, 41, 7, 39, 47, 73, 81, 401, 57, 441, 571, 957, 997, 1, 19, 291, 173, 9, 417