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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 0 |
| 5 | -16 |
| 6 | -35 |
| 7 | 342 |
| 8 | 2779 |
| 9 | -6424 |
| 10 | -239382 |
| 11 | -822460 |
| 12 | 22393657 |
| 13 | 278844084 |
| 14 | -1553468891 |
| 15 | -68399947042 |
| 16 | -275025888900 |
| 17 | 15302175612416 |
| 18 | 243541868882077 |
| 19 | -2463105309082902 |
| 20 | -121649966081262521 |
| 21 | -473088821582805820 |
| 22 | 50905612811064360006 |
| 23 | 945133249101683013812 |
| 24 | -15321255878414345388335 |