A047814 Largest prime substring of n, or 0 if no such substring exists.

0, 0, 2, 3, 0, 5, 0, 7, 0, 0, 0, 11, 2, 13, 0, 5, 0, 17, 0, 19, 2, 2, 2, 23, 2, 5, 2, 7, 2, 29, 3, 31, 3, 3, 3, 5, 3, 37, 3, 3, 0, 1, 2, 43, 0, 5, 0, 47, 0, 0, 5, 5, 5, 53, 5, 5, 5, 7, 5, 59, 0, 61, 2, 3, 0, 5, 0, 67, 0, 0, 7, 71, 7, 73, 7, 7, 7, 7, 7, 79, 0, 0, 2, 83, 0, 5, 0, 7, 0, 89