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 | 4 |
| 2 | 58 |
| 3 | 1000 |
| 4 | 19426 |
| 5 | 412744 |
| 6 | 9195796 |
| 7 | 212836432 |
| 8 | 5062716850 |
| 9 | 123033947464 |
| 10 | 3041489363188 |
| 11 | 76243484446672 |
| 12 | 1933564156575364 |
| 13 | 49518970223489680 |
| 14 | 1278877982692134568 |
| 15 | 33269141292429734560 |
| 16 | 870987510534775369810 |
| 17 | 22930499187530338390600 |
| 18 | 606700679139764282611540 |