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) |
|---|---|
| 4 | 1 |
| 5 | 6 |
| 6 | 35 |
| 7 | 225 |
| 8 | 2464 |
| 9 | 29932 |
| 10 | 375164 |
| 11 | 4877100 |
| 12 | 73016856 |
| 13 | 1229669496 |
| 14 | 22393143552 |
| 15 | 430226343456 |
| 16 | 8838633396384 |
| 17 | 195021406776960 |
| 18 | 4592633620285440 |
| 19 | 114230969866103040 |
| 20 | 2991995263667137536 |
| 21 | 82505359191832358400 |