First generalized repunit (probable) prime in negative bases b=-706.

Now there are 63 negative bases -1024<=b<=-2 remain (in absolute values):

{97, 103, 113, 186, 187, 220, 304, 306, 309, 335, 414, 416, 428, 433, 445, 459, 486, 498, 530, 539, 545, 550, 557, 560, 587, 592, 596, 597, 598, 617, 624, 637, 659, 665, 671, 677, 696, 701, 717, 726, 730, 740, 754, 766, 790, 821, 833, 851, 873, 890, 914, 923, 929, 943, 944, 965, 966, 983, 984, 985, 996, 1004, 1005}

These negative bases -1024<=b<=-2 (in absolute values) have no possible prime because of algebra factors:

{8, 27, 32, 64, 125, 243, 324, 512, 1000, 1024}

To be completed...