Generalized repunit prime (base -237).
For base -240, I found R2, R7.
For base -239, I found R59, R601, R8867.
For base -238, I found R23, R353.
For base -237, I found R3, R8677.
For base -236, I found R11, R71, R149, R827, R1741.
For base -235, I found R223, R1993, R6043, R9137.

To be completed...