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 | 41 |
| 4 | 444 |
| 5 | 5979 |
| 6 | 96375 |
| 7 | 1810297 |
| 8 | 38845520 |
| 9 | 937702437 |
| 10 | 25154615815 |
| 11 | 742476758297 |
| 12 | 23915618605956 |
| 13 | 834831863473087 |
| 14 | 31395048114431183 |
| 15 | 1265451184688113105 |
| 16 | 54426870391856267072 |
| 17 | 2488054366709505840265 |
| 18 | 120468464465317265258991 |
| 19 | 6158924799179729969013985 |