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 | -2 |
| 5 | -1 |
| 6 | 9 |
| 7 | -20 |
| 8 | 20 |
| 9 | 24 |
| 10 | -150 |
| 11 | 327 |
| 12 | -293 |
| 13 | -599 |
| 14 | 3097 |
| 15 | -6452 |
| 16 | 4854 |
| 17 | 15878 |
| 18 | -71252 |
| 19 | 140112 |
| 20 | -81328 |
| 21 | -437346 |
| 22 | 1746254 |
| 23 | -3214989 |
| 24 | 1223971 |
| 25 | 12345295 |
| 26 | -44552833 |
| 27 | 76242173 |
| 28 | -11292089 |
| 29 | -354175849 |
| 30 | 1167638037 |
| 31 | -1842585992 |
| 32 | -233903034 |
| 33 | 10273377388 |
| 34 | -31169512310 |