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 | 1 |
| 1 | 1 |
| 2 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 4 |
| 6 | 0 |
| 7 | 2 |
| 8 | 10 |
| 9 | 32 |
| 10 | 38 |
| 11 | 140 |
| 12 | 496 |
| 13 | 1186 |
| 14 | 3178 |
| 15 | 16792 |
| 16 | 82038 |
| 17 | 289566 |
| 18 | 1139874 |
| 19 | 5914118 |
| 20 | 33800010 |
| 21 | 142337180 |
| 22 | 721286448 |
| 23 | 4384569864 |