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 | 0 |
| 1 | 1 |
| 2 | -10 |
| 3 | 178 |
| 4 | -5296 |
| 5 | 238816 |
| 6 | -15214480 |
| 7 | 1301989648 |
| 8 | -144118832896 |
| 9 | 20040052293376 |
| 10 | -3419989086092800 |
| 11 | 702831038438522368 |
| 12 | -171209091176316215296 |
| 13 | 48783404012394865985536 |
| 14 | -16074763418934659189278720 |
| 15 | 6065554251200571899397081088 |
| 16 | -2598468976240882751482797162496 |