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 | -3 |
| 2 | 12 |
| 3 | -64 |
| 4 | 441 |
| 5 | -3771 |
| 6 | 38638 |
| 7 | -461742 |
| 8 | 6306009 |
| 9 | -96885451 |
| 10 | 1653938616 |
| 11 | -31057949748 |
| 12 | 636230845297 |
| 13 | -14119481897379 |
| 14 | 337448486204586 |
| 15 | -8640908986912786 |
| 16 | 236015269236658833 |
| 17 | -6849355531826261427 |
| 18 | 210466462952536609924 |