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 | 25 |
| 4 | -173 |
| 5 | 1292 |
| 6 | -10105 |
| 7 | 81565 |
| 8 | -673691 |
| 9 | 5662878 |
| 10 | -48263038 |
| 11 | 415950272 |
| 12 | -3617999891 |
| 13 | 31714089336 |
| 14 | -279828926113 |
| 15 | 2483097203637 |
| 16 | -22143011361045 |
| 17 | 198317403322755 |