Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 285: | \[{21^{285}-1\over20}\] | 5 × 211 × 463 × 571 × 9391 × 18181 × 40841 × 304609 × 12061389013<11> × 19449969211<11> × 54921106624003<14> × 619598441951897251<18> × 2522688573446019221<19> × 694155614288478272051619864571<30> × 1244541772187848099210936765314595053007129<43> × 4962575794097659196896553056277931780683391554141<49> × [66470322838106444567481701411888139523258442754511850465204782608795045255251352068847644054704322699705340905151687277116022706671410660051638592550233913801<158>] |