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 | -19 |
| 2 | 399 |
| 3 | -9177 |
| 4 | 228969 |
| 5 | -6146595 |
| 6 | 176336055 |
| 7 | -5376116025 |
| 8 | 173372815665 |
| 9 | -5890443433875 |
| 10 | 210126743128575 |
| 11 | -7846697354074425 |
| 12 | 305934601802254425 |
| 13 | -12425119660246968675 |
| 14 | 524572676975580207975 |
| 15 | -22979378711569440785625 |