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) |
|---|---|
| 2 | 1 |
| 3 | 0 |
| 4 | 1 |
| 5 | 1 |
| 6 | -2 |
| 7 | 2 |
| 8 | 0 |
| 9 | 5 |
| 10 | -10 |
| 11 | 6 |
| 12 | 1 |
| 13 | -10 |
| 14 | 40 |
| 15 | -54 |
| 16 | 24 |
| 17 | 0 |
| 18 | 21 |
| 19 | -140 |
| 20 | 336 |
| 21 | -336 |
| 22 | 120 |
| 23 | 1 |
| 24 | -42 |
| 25 | 462 |
| 26 | -1764 |
| 27 | 3024 |
| 28 | -2400 |
| 29 | 720 |
| 30 | 0 |
| 31 | 85 |
| 32 | -1470 |
| 33 | 8442 |
| 34 | -22176 |
| 35 | 29520 |
| 36 | -19440 |
| 37 | 5040 |
| 38 | 1 |
| 39 | -170 |
| 40 | 4580 |
| 41 | -38178 |
| 42 | 144648 |
| 43 | -288000 |
| 44 | 313200 |
| 45 | -176400 |
| 46 | 40320 |
| 47 | 0 |
| 48 | 341 |
| 49 | -14080 |
| 50 | 166452 |
| 51 | -875952 |
| 52 | 2451240 |
| 53 | -3920400 |
| 54 | 3603600 |
| 55 | -1774080 |
| 56 | 362880 |