Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 327: | \[{21^{327}-1\over20}\] | 463 × 961458481 × 252649631352967<15> × 243559381356675673<18> × 1075844735830122358017703049625189977667287013021268821502115973717283800539785976074877960131456456976157869419<112> × [3938172419152858154817497203969841611773037176100739992840748911294956098293577995633305875948064762901450976392814188559614222786760479891077952898737359461257067217712359944634962558035951566996905381565026166142900898815382548451074844576486316883641614304138324379828896481<277>] |