Base 15 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
64: | \[{15^{64}-1\over14}\] | 29 × 17 × 113 × 257 × 1489 × 2689 × 7121 × 179953 × 1391359510721<13> × 12779004583099009<17> × 5765807395792521302977<22> |