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) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 17 |
| 4 | 74 |
| 5 | 327 |
| 6 | 1461 |
| 7 | 6584 |
| 8 | 29879 |
| 9 | 136391 |
| 10 | 625731 |
| 11 | 2883357 |
| 12 | 13338421 |
| 13 | 61920497 |
| 14 | 288368511 |
| 15 | 1346873365 |
| 16 | 6307694990 |
| 17 | 29613690966 |
| 18 | 139352892908 |
| 19 | 657163401162 |
| 20 | 3105304341356 |
| 21 | 14701236957028 |
| 22 | 69722518168060 |
| 23 | 331220099616432 |