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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 10 |
| 6 | 41 |
| 7 | 140 |
| 8 | 659 |
| 9 | 2885 |
| 10 | 14956 |
| 11 | 77990 |
| 12 | 452409 |
| 13 | 2678676 |
| 14 | 17176251 |
| 15 | 113458801 |
| 16 | 795016044 |
| 17 | 5760341506 |
| 18 | 43802563937 |
| 19 | 344138100628 |
| 20 | 2817486388739 |
| 21 | 23809341016525 |
| 22 | 208552149482436 |
| 23 | 1882541647472398 |
| 24 | 17549345518850193 |