Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
257: | \[{3^{257}-1\over2}\] | 120277 × 1329772662933524112502310453951741137<37> × 1303684432177220040931228503924522275783855152532699243445654450720942101263148269<82> |