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 | 20 |
| 2 | -1282 |
| 3 | -92920 |
| 4 | 4610572 |
| 5 | 717377200 |
| 6 | -24427366520 |
| 7 | -7728318032800 |
| 8 | 133041452750480 |
| 9 | 106653076504366400 |
| 10 | 119080018350561760 |
| 11 | -1791523146436431612800 |
| 12 | -38033681428250725939520 |
| 13 | 35399429559107921153964800 |
| 14 | 1539633069292288796472840320 |