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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 23 |
| 7 | 63 |
| 8 | 188 |
| 9 | 596 |
| 10 | 1979 |
| 11 | 6804 |
| 12 | 24118 |
| 13 | 87379 |
| 14 | 322652 |
| 15 | 1209808 |
| 16 | 4596158 |
| 17 | 17657037 |
| 18 | 68497898 |
| 19 | 268006183 |
| 20 | 1056597059 |
| 21 | 4193905901 |
| 22 | 16748682185 |
| 23 | 67258011248 |
| 24 | 271452424286 |
| 25 | 1100632738565 |
| 26 | 4481533246014 |
| 27 | 18319020658537 |
| 28 | 75152228262785 |
| 29 | 309337095953934 |