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 | 7 |
| 3 | 59 |
| 4 | 605 |
| 5 | 7365 |
| 6 | 104055 |
| 7 | 1675275 |
| 8 | 30290085 |
| 9 | 607828725 |
| 10 | 13406691375 |
| 11 | 322415322075 |
| 12 | 8396547684525 |
| 13 | 235419569309925 |
| 14 | 7070492932878375 |
| 15 | 226469231898784875 |
| 16 | 7706144167912315125 |
| 17 | 277613088828805855125 |
| 18 | 10555630035365385345375 |