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 | -7 |
| 2 | 1 |
| 3 | 56 |
| 4 | -15 |
| 5 | 1 |
| 6 | -504 |
| 7 | 191 |
| 8 | -24 |
| 9 | 1 |
| 10 | 5040 |
| 11 | -2414 |
| 12 | 431 |
| 13 | -34 |
| 14 | 1 |
| 15 | -55440 |
| 16 | 31594 |
| 17 | -7155 |
| 18 | 805 |
| 19 | -45 |
| 20 | 1 |
| 21 | 665280 |
| 22 | -434568 |
| 23 | 117454 |
| 24 | -16815 |
| 25 | 1345 |
| 26 | -57 |
| 27 | 1 |
| 28 | -8648640 |
| 29 | 6314664 |
| 30 | -1961470 |
| 31 | 336049 |
| 32 | -34300 |
| 33 | 2086 |
| 34 | -70 |
| 35 | 1 |
| 36 | 121080960 |
| 37 | -97053936 |
| 38 | 33775244 |
| 39 | -6666156 |
| 40 | 816249 |
| 41 | -63504 |
| 42 | 3066 |
| 43 | -84 |
| 44 | 1 |