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 | 63 |
| 3 | 583 |
| 4 | 5407 |
| 5 | 50007 |
| 6 | 460815 |
| 7 | 4231815 |
| 8 | 38745279 |
| 9 | 353832631 |
| 10 | 3224323183 |
| 11 | 29328492519 |
| 12 | 266364307231 |
| 13 | 2416023142423 |
| 14 | 21890268365007 |
| 15 | 198151683934023 |
| 16 | 1792260214473087 |
| 17 | 16199857938091383 |
| 18 | 146342491104098607 |
| 19 | 1321339563995562663 |
| 20 | 11925412051760977887 |
| 21 | 107590261672922633943 |