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 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | -1 |
| 4 | 3 |
| 5 | -1 |
| 6 | -5 |
| 7 | 7 |
| 8 | 3 |
| 9 | -17 |
| 10 | 11 |
| 11 | 23 |
| 12 | -45 |
| 13 | -1 |
| 14 | 91 |
| 15 | -89 |
| 16 | -93 |
| 17 | 271 |
| 18 | -85 |
| 19 | -457 |
| 20 | 627 |
| 21 | 287 |
| 22 | -1541 |
| 23 | 967 |
| 24 | 2115 |
| 25 | -4049 |
| 26 | -181 |
| 27 | 8279 |
| 28 | -7917 |
| 29 | -8641 |
| 30 | 24475 |
| 31 | -7193 |
| 32 | -41757 |
| 33 | 56143 |
| 34 | 27371 |
| 35 | -139657 |
| 36 | 84915 |
| 37 | 194399 |
| 38 | -364229 |
| 39 | -24569 |
| 40 | 753027 |
| 41 | -703889 |