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) |
|---|---|
| 1 | 0 |
| 2 | 3 |
| 3 | 35 |
| 4 | 575 |
| 5 | 14399 |
| 6 | 518399 |
| 7 | 25401599 |
| 8 | 1625702399 |
| 9 | 131681894399 |
| 10 | 13168189439999 |
| 11 | 1593350922239999 |
| 12 | 229442532802559999 |
| 13 | 38775788043632639999 |
| 14 | 7600054456551997439999 |
| 15 | 1710012252724199423999999 |
| 16 | 437763136697395052543999999 |
| 17 | 126513546505547170185215999999 |