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 | 4 |
| 3 | 6 |
| 4 | 0 |
| 5 | -20 |
| 6 | -48 |
| 7 | -56 |
| 8 | 0 |
| 9 | 144 |
| 10 | 320 |
| 11 | 352 |
| 12 | 0 |
| 13 | -832 |
| 14 | -1792 |
| 15 | -1920 |
| 16 | 0 |
| 17 | 4352 |
| 18 | 9216 |
| 19 | 9728 |
| 20 | 0 |
| 21 | -21504 |
| 22 | -45056 |
| 23 | -47104 |
| 24 | 0 |
| 25 | 102400 |
| 26 | 212992 |
| 27 | 221184 |
| 28 | 0 |
| 29 | -475136 |
| 30 | -983040 |
| 31 | -1015808 |
| 32 | 0 |
| 33 | 2162688 |
| 34 | 4456448 |
| 35 | 4587520 |
| 36 | 0 |
| 37 | -9699328 |
| 38 | -19922944 |
| 39 | -20447232 |
| 40 | 0 |
| 41 | 42991616 |