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 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 45 |
| 4 | 236 |
| 5 | 1306 |
| 6 | 8088 |
| 7 | 57078 |
| 8 | 457416 |
| 9 | 4118031 |
| 10 | 41182312 |
| 11 | 453008435 |
| 12 | 5436105588 |
| 13 | 70669378832 |
| 14 | 989371312216 |
| 15 | 14840569694868 |
| 16 | 237449115133392 |
| 17 | 4036634957288013 |
| 18 | 72659429231210568 |
| 19 | 1380529155393034441 |
| 20 | 27610583107860731324 |
| 21 | 579822245265075410934 |