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 | 3 |
| 3 | 6 |
| 4 | 19 |
| 5 | 57 |
| 6 | 258 |
| 7 | 1110 |
| 8 | 5475 |
| 9 | 27429 |
| 10 | 143379 |
| 11 | 764970 |
| 12 | 4173906 |
| 13 | 23140816 |
| 14 | 130205922 |
| 15 | 741650802 |
| 16 | 4270593219 |
| 17 | 24825326199 |
| 18 | 145535320383 |
| 19 | 859627488966 |
| 20 | 5112006997539 |
| 21 | 30586307211945 |
| 22 | 184023410798910 |
| 23 | 1112800162657902 |
| 24 | 6760426635625170 |