Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 381: | \[{21^{381}-1\over20}\] | 463 × 509 × 85853 × 101347 × 123564234215209<15> × 526073566316093<15> × 21045416332383383<17> × 6619201108364006378440292620708869500505245589624095987<55> × 105546738449008968050440888723415799976700232611051102641043<60> × [14869931703597493999966771964246918572785761983212971379090519214253398778321825210861217321467791711781072831363531941385551254258262833868088725574113790861919224731804475130100738595113010271109080933067593023397541594569563368909131063166613011726828192785852296613514765597251648954963294150066098626036857242448185145435043<329>] |