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 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 6 |
| 6 | 7 |
| 7 | 25 |
| 8 | 80 |
| 9 | 255 |
| 10 | 795 |
| 11 | 2919 |
| 12 | 10378 |
| 13 | 36590 |
| 14 | 130716 |
| 15 | 480773 |
| 16 | 1774714 |
| 17 | 6543633 |
| 18 | 24208803 |
| 19 | 90331307 |
| 20 | 339178346 |
| 21 | 1277308160 |
| 22 | 4819109576 |