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 | -1 |
| 2 | 0 |
| 3 | 0 |
| 4 | -2 |
| 5 | -75 |
| 6 | -3334 |
| 7 | -192864 |
| 8 | -14443260 |
| 9 | -1372372623 |
| 10 | -162009663365 |
| 11 | -23314158802286 |
| 12 | -4022712394579207 |
| 13 | -820399656345934444 |
| 14 | -195326656416326556562 |
| 15 | -53709209673236813446542 |
| 16 | -16896296201917398543629108 |
| 17 | -6030879950631118091070849321 |