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 | -3 |
| 3 | 1 |
| 4 | 1 |
| 5 | -1 |
| 6 | 5 |
| 7 | -19 |
| 8 | -9 |
| 9 | 41 |
| 10 | -103 |
| 11 | 17 |
| 12 | 289 |
| 13 | -169 |
| 14 | 331 |
| 15 | -689 |
| 16 | -4991 |
| 17 | 3999 |
| 18 | 7833 |
| 19 | -6509 |
| 20 | 21827 |
| 21 | -22165 |
| 22 | -87637 |
| 23 | 119441 |
| 24 | -190981 |
| 25 | -152513 |
| 26 | 1482023 |
| 27 | -425985 |
| 28 | -1045091 |
| 29 | 1071237 |
| 30 | -14108791 |
| 31 | 5845271 |
| 32 | 39852203 |
| 33 | -35832801 |
| 34 | 54451699 |
| 35 | 44061359 |
| 36 | -435442725 |
| 37 | 261309855 |
| 38 | -22217917 |