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 | 6 |
| 3 | 62 |
| 4 | 900 |
| 5 | 16824 |
| 6 | 384668 |
| 7 | 10398480 |
| 8 | 324420840 |
| 9 | 11472953760 |
| 10 | 453518054216 |
| 11 | 19815916826160 |
| 12 | 948348447031440 |
| 13 | 49334804947402800 |
| 14 | 2771902062752597520 |
| 15 | 167281797371598801136 |
| 16 | 10791777047497882651296 |
| 17 | 741135302021991803931360 |
| 18 | 53983717302568691555767360 |