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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 16 |
| 5 | 60 |
| 6 | 231 |
| 7 | 877 |
| 8 | 3362 |
| 9 | 12905 |
| 10 | 49825 |
| 11 | 193003 |
| 12 | 750581 |
| 13 | 2927792 |
| 14 | 11453171 |
| 15 | 44911853 |
| 16 | 176499605 |
| 17 | 694954416 |
| 18 | 2741031257 |
| 19 | 10827727980 |
| 20 | 42831355495 |
| 21 | 169640762209 |
| 22 | 672657218163 |
| 23 | 2669990735153 |
| 24 | 10608176066076 |
| 25 | 42184579054003 |