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 | -10 |
| 3 | 221 |
| 4 | -6082 |
| 5 | 187386 |
| 6 | -6184848 |
| 7 | 213843477 |
| 8 | -7645509706 |
| 9 | 280351640702 |
| 10 | -10485617230780 |
| 11 | 398467433529298 |
| 12 | -15341431926699284 |
| 13 | 597149747213056324 |
| 14 | -23459916801814723548 |
| 15 | 929028306450848244741 |
| 16 | -37045540042729366580442 |