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 | 2 |
| 3 | 2 |
| 4 | 10 |
| 5 | 2 |
| 6 | 64 |
| 7 | 2 |
| 8 | 330 |
| 9 | 1028 |
| 10 | 2010 |
| 11 | 2 |
| 12 | 24216 |
| 13 | 2 |
| 14 | 77528 |
| 15 | 964696 |
| 16 | 490314 |
| 17 | 2 |
| 18 | 11437750 |
| 19 | 2 |
| 20 | 21390330 |