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 | 0 |
| 2 | 1 |
| 3 | 11 |
| 4 | 125 |
| 5 | 1649 |
| 6 | 25519 |
| 7 | 458569 |
| 8 | 9433353 |
| 9 | 219117905 |
| 10 | 5677963451 |
| 11 | 162457597961 |
| 12 | 5087919552253 |
| 13 | 173136159558361 |
| 14 | 6361282619516343 |
| 15 | 250987334850557369 |
| 16 | 10584205713321808529 |
| 17 | 475079402305823570849 |
| 18 | 22614513693572549266291 |
| 19 | 1137911105533216112417161 |