Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
79: | \[{20^{79}-1\over19}\] | 26861 × 7731160503875069<16> × 4178614725165165091<19> × 52283868973702536169<20> × 7012116809755762514267308698568975988864311<43> |