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 | -1024 |
| 1 | 14336 |
| 2 | -106496 |
| 3 | 559104 |
| 4 | -2329600 |
| 5 | 8200192 |
| 6 | -25346048 |
| 7 | 70606848 |
| 8 | -180590592 |
| 9 | 429977600 |
| 10 | -963149824 |
| 11 | 2046693376 |
| 12 | -4153583616 |
| 13 | 8094162944 |
| 14 | -15214592000 |
| 15 | 27690557440 |
| 16 | -48952949760 |
| 17 | 84293314560 |
| 18 | -141710499840 |
| 19 | 233076480000 |