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 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 2 |
| 6 | 3 |
| 7 | 4 |
| 8 | 6 |
| 9 | 10 |
| 10 | 16 |
| 11 | 29 |
| 12 | 59 |
| 13 | 140 |
| 14 | 400 |
| 15 | 1413 |
| 16 | 6467 |
| 17 | 40261 |
| 18 | 361139 |
| 19 | 4990906 |
| 20 | 114916199 |
| 21 | 4833601540 |