Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
211: | \[{3^{211}-1\over2}\] | 2111 × 962188370639<12> × 54046656969013<14> × 5676687374958905209<19> × 1695949409060064182746451<25> × 22260233052088235975354234411<29> |