A037272 Primes reached in A037271, or -1 if no such prime exists.

211, 23, 3331113965338635107, 311, 773, 223, 13367, 1129, 31636373, 233, 3318308475676071413, 37, 211, 331319, 773, 3251, 13367, 227, 547, 241271, 311, 31397, 1129, 71129, 373, 313, 3314192745739, 379, 22815088913, 3411949