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 | 5 |
| 3 | 36 |
| 4 | 350 |
| 5 | 4328 |
| 6 | 65132 |
| 7 | 1155904 |
| 8 | 23640724 |
| 9 | 547544032 |
| 10 | 14166236708 |
| 11 | 404944248104 |
| 12 | 12674392793900 |
| 13 | 431104742439088 |
| 14 | 15834117059443828 |
| 15 | 624575921756875960 |
| 16 | 26332801242942780668 |
| 17 | 1181750740315156943936 |
| 18 | 56244454481507648435012 |