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 | 4 |
| 3 | -2 |
| 4 | -64 |
| 5 | -95 |
| 6 | 780 |
| 7 | 5230 |
| 8 | 19228 |
| 9 | -90488 |
| 10 | -1454232 |
| 11 | -4080620 |
| 12 | 19557280 |
| 13 | 270109125 |
| 14 | 1702743364 |
| 15 | -35378580 |
| 16 | -74674412048 |
| 17 | -515950535521 |
| 18 | -1719717134140 |
| 19 | 9100931191804 |
| 20 | 173629815007712 |
| 21 | 988336433707663 |
| 22 | 2065106985108344 |
| 23 | -25897495149473592 |