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 | -1 |
| 2 | 2 |
| 3 | 1 |
| 4 | -8 |
| 5 | 8 |
| 6 | 1 |
| 7 | -32 |
| 8 | 160 |
| 9 | -256 |
| 10 | 128 |
| 11 | 1 |
| 12 | -128 |
| 13 | 2688 |
| 14 | -21504 |
| 15 | 84480 |
| 16 | -180224 |
| 17 | 212992 |
| 18 | -131072 |
| 19 | 32768 |
| 20 | 1 |
| 21 | -512 |
| 22 | 43520 |
| 23 | -1462272 |
| 24 | 25798656 |
| 25 | -275185664 |
| 26 | 1926299648 |
| 27 | -9313976320 |
| 28 | 32133218304 |
| 29 | -80648077312 |
| 30 | 148562247680 |
| 31 | -200655503360 |