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) |
|---|---|
| 6 | 1 |
| 7 | 126 |
| 8 | 3822 |
| 9 | 105336 |
| 10 | 2312163 |
| 11 | 41420610 |
| 12 | 868380535 |
| 13 | 16453085220 |
| 14 | 312866654100 |
| 15 | 6063351173880 |
| 16 | 127050688947000 |
| 17 | 2603853165950400 |
| 18 | 56141875342402480 |
| 19 | 1242418296237553440 |
| 20 | 28627706535786406800 |
| 21 | 683460419058369489600 |
| 22 | 16802904218347937067840 |