Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 201: | \[{21^{201}-1\over20}\] | 269 × 463 × 4797582169<10> × 324363426169571<15> × 312929837239650768379490219650039<33> × 71028332352256443443129296219339913167<38> × 178567538270106482711574632719239220215367907500387<51> × 3792971418457965389675832305015939195690902455910881351101537130499197325189758118422778432861005947731663484547307<115> |