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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | -3 |
| 9 | 0 |
| 10 | 0 |
| 11 | 0 |
| 12 | 0 |
| 13 | 0 |
| 14 | -24 |
| 15 | -24 |
| 16 | 54 |
| 17 | 0 |
| 18 | 0 |
| 19 | 0 |
| 20 | -252 |
| 21 | -504 |
| 22 | 900 |
| 23 | 1152 |
| 24 | -1452 |
| 25 | -3312 |
| 26 | -7344 |
| 27 | 11484 |
| 28 | 35856 |
| 29 | -30132 |
| 30 | -50184 |
| 31 | 264 |
| 32 | -113160 |
| 33 | 175464 |
| 34 | 712176 |
| 35 | -319098 |
| 36 | -1997856 |
| 37 | 334320 |
| 38 | 341856 |
| 39 | 1211472 |
| 40 | 13301112 |
| 41 | -2785392 |