Base 31 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
85: | \[{31^{85}-1\over30}\] | 5 × 11 × 17351 × 108971 × 391206807721<12> × 21736504684553261<17> × 751670559138758105956097<24> × 292415865518548212725264181682005402545390163298379652017348311<63> |