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 | 1 |
| 1 | 64 |
| 2 | 2144 |
| 3 | 49920 |
| 4 | 905840 |
| 5 | 13627264 |
| 6 | 176638592 |
| 7 | 2025205248 |
| 8 | 20930373880 |
| 9 | 197788352320 |
| 10 | 1728062919232 |
| 11 | 14083242424576 |
| 12 | 107837287452608 |
| 13 | 780481475916160 |
| 14 | 5366307146732800 |
| 15 | 35202669371599360 |
| 16 | 221142159585764508 |
| 17 | 1334633003840266624 |
| 18 | 7760187771579170400 |