This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 7 |
| 2 | 67 |
| 3 | 697 |
| 4 | 7547 |
| 5 | 83682 |
| 6 | 942649 |
| 7 | 10739176 |
| 8 | 123388763 |
| 9 | 1427090845 |
| 10 | 16593192942 |
| 11 | 193774331494 |
| 12 | 2271115189673 |
| 13 | 26700463884244 |
| 14 | 314735943548632 |
| 15 | 3718522618187472 |
| 16 | 44021808206431579 |
| 17 | 522080025971331983 |
| 18 | 6201449551502245321 |
| 19 | 73767447652621434695 |
| 20 | 878599223738760686422 |