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) |
|---|---|
| 1 | 1 |
| 2 | -7 |
| 3 | 39 |
| 4 | -231 |
| 5 | 1175 |
| 6 | -6404 |
| 7 | 34516 |
| 8 | -194372 |
| 9 | 914065 |
| 10 | -4380707 |
| 11 | 19511875 |
| 12 | -48269825 |
| 13 | 364029100 |
| 14 | -2195115952 |
| 15 | 13627012744 |
| 16 | -115725814173 |
| 17 | 792363218461 |
| 18 | -5961225064275 |
| 19 | 50261904138348 |
| 20 | -425928565835370 |
| 21 | 3704468293623774 |
| 22 | -34926740161083290 |
| 23 | 389473974875205556 |