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 | -30 |
| 2 | -11340 |
| 3 | -3912600 |
| 4 | -1520905170 |
| 5 | -636170644008 |
| 6 | -278687199310200 |
| 7 | -126000360658968000 |
| 8 | -58290111778749466140 |
| 9 | -27440829122946510954630 |
| 10 | -13096614404248661886145848 |
| 11 | -6320198941502349713305002120 |
| 12 | -3077986352751848627729986859400 |