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 | 7 |
| 3 | 90 |
| 4 | 1701 |
| 5 | 42525 |
| 6 | 1323652 |
| 7 | 49329280 |
| 8 | 2141764053 |
| 9 | 106175395755 |
| 10 | 5917584964655 |
| 11 | 366282500870286 |
| 12 | 24930204590758260 |
| 13 | 1850568574253550060 |
| 14 | 148782988064375309400 |
| 15 | 12879868072770626040000 |
| 16 | 1194461517469807833782085 |
| 17 | 118144018577011378596484455 |