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 | 1 |
| 2 | 6 |
| 3 | 31 |
| 4 | 198 |
| 5 | 1270 |
| 6 | 8838 |
| 7 | 63419 |
| 8 | 475796 |
| 9 | 3697876 |
| 10 | 29793899 |
| 11 | 248312750 |
| 12 | 2139071800 |
| 13 | 19023864211 |
| 14 | 174495408060 |
| 15 | 1648972635108 |
| 16 | 16036927429350 |
| 17 | 160338342813918 |
| 18 | 1646265278973845 |
| 19 | 17340402062779049 |
| 20 | 187190960572134321 |