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 | 3 |
| 3 | 10 |
| 4 | 69 |
| 5 | 626 |
| 6 | 7866 |
| 7 | 117650 |
| 8 | 2101265 |
| 9 | 43047451 |
| 10 | 1000390658 |
| 11 | 25937424602 |
| 12 | 743069105634 |
| 13 | 23298085122482 |
| 14 | 793728614541474 |
| 15 | 29192926269590300 |
| 16 | 1152925902670135553 |
| 17 | 48661191875666868482 |
| 18 | 2185913413229070900339 |
| 19 | 104127350297911241532842 |