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 | 5 |
| 3 | 24 |
| 4 | 130 |
| 5 | 815 |
| 6 | 5871 |
| 7 | 47950 |
| 8 | 438404 |
| 9 | 4438845 |
| 10 | 49320505 |
| 11 | 596778116 |
| 12 | 7812368070 |
| 13 | 110024183659 |
| 14 | 1658826153635 |
| 15 | 26659706040570 |
| 16 | 454992316425736 |
| 17 | 8218298715439865 |
| 18 | 156631104929559789 |
| 19 | 3141323826642838000 |