Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 221: | \[{20^{221}-1\over19}\] | 3121 × 142559 × 9690539 × 170587691 × 689852631578947368421<21> × [34957074649760906831419584094087417577344990467546164804287965727348304131681987269180192833352195892952597507671392121690529961904066908012112933537331040222702995711575573515569401750839102794860531626615146179883622653397657812026094661191<242>] |