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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 8 |
| 5 | 22 |
| 6 | 53 |
| 7 | 151 |
| 8 | 435 |
| 9 | 1314 |
| 10 | 4239 |
| 11 | 13705 |
| 12 | 45746 |
| 13 | 153850 |
| 14 | 525236 |
| 15 | 1817111 |
| 16 | 6341424 |
| 17 | 22336060 |
| 18 | 79287664 |
| 19 | 283277225 |
| 20 | 1018369893 |