Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
278: | \[{5^{278}-1\over4}\] | 2 × 3 × 21521602057721<14> × 172694671812043<15> × 417786018853823<15> × 2459716746919477501<19> × 6789441546024769741462601111<28> × 13476012762896826693076454784079583396699156093189<50> × 24550591546653776667941845268908441565415743319193209001<56> |