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 | 51 |
| 4 | -996 |
| 5 | 27120 |
| 6 | -943602 |
| 7 | 40023354 |
| 8 | -2002953432 |
| 9 | 115536775248 |
| 10 | -7547711366880 |
| 11 | 550798542893808 |
| 12 | -44409102801760584 |
| 13 | 3920444594317227600 |
| 14 | -376109365694009875704 |
| 15 | 38961901445878423746360 |
| 16 | -4334496557343337848950208 |
| 17 | 515407133679990302374396416 |