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) |
|---|---|
| 5 | 1 |
| 6 | -15 |
| 7 | 175 |
| 8 | -1960 |
| 9 | 22449 |
| 10 | -269451 |
| 11 | 3423860 |
| 12 | -46238280 |
| 13 | 664233856 |
| 14 | -10143487354 |
| 15 | 164423204582 |
| 16 | -2823783679080 |
| 17 | 51273355515264 |
| 18 | -982236541934430 |
| 19 | 19809898439192946 |
| 20 | -419752648063849626 |
| 21 | 9325875631405818996 |
| 22 | -216846992855331506052 |
| 23 | 5267598064689049209252 |