Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 305: | \[{21^{305}-1\over20}\] | 5 × 15373 × 40841 × 47581 × 12519763 × 1128331159687<13> × 1814065850324073713<19> × 6603983842892247521<19> × 57398774322642953389748085156004642469<38> × [651931515467108294732282458658159904901882518094311979856221194890683664987905666506760613186398488556546836324607545894013486690165398469882484166777827916722411076296025598787758893747280176160897822962689892033347355185165015874698064578296448211727047265682048718904979134218383288759499701<294>] |