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 | -60 |
| 5 | -768 |
| 6 | -5008 |
| 7 | -20672 |
| 8 | -46720 |
| 9 | 76800 |
| 10 | 1540608 |
| 11 | 10610688 |
| 12 | 55114752 |
| 13 | 246005760 |
| 14 | 992808960 |
| 15 | 3720331264 |
| 16 | 13156941824 |
| 17 | 44395134976 |
| 18 | 144054681600 |
| 19 | 452151214080 |
| 20 | 1379061202944 |
| 21 | 4102054477824 |
| 22 | 11934819680256 |
| 23 | 34047283691520 |
| 24 | 95430020956160 |
| 25 | 263252302888960 |