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 | -2 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | -24 |
| 12 | 26 |
| 13 | 0 |
| 14 | 0 |
| 15 | -48 |
| 16 | -252 |
| 17 | 720 |
| 18 | -438 |
| 19 | -192 |
| 20 | -984 |
| 21 | -1008 |
| 22 | 12924 |
| 23 | -19536 |
| 24 | 3062 |
| 25 | -8280 |
| 26 | 26694 |
| 27 | 153536 |
| 28 | -507948 |
| 29 | 406056 |
| 30 | -79532 |
| 31 | 729912 |
| 32 | 631608 |
| 33 | -9279376 |
| 34 | 15771600 |
| 35 | -7467336 |
| 36 | 10935114 |
| 37 | -21835524 |
| 38 | -112752684 |
| 39 | 400576168 |
| 40 | -410287368 |