Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 153: | \[{3^{153}-1\over2}\] | 13 × 757 × 1871 × 12853 × 34511 × 6213394261<10> × 35106034213<11> × 99810171997<11> × 28090626041813012073462457<26> |