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 | -4 |
| 2 | 26 |
| 3 | -308 |
| 4 | 6959 |
| 5 | -306888 |
| 6 | 26732904 |
| 7 | -4628215312 |
| 8 | 1597488685120 |
| 9 | -1101039613155676 |
| 10 | 1516536435306750724 |
| 11 | -4175994577753360618608 |
| 12 | 22993788379965461938093352 |
| 13 | -253190775338116964702467771168 |