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 | -2 |
| 3 | 0 |
| 4 | 6 |
| 5 | 4 |
| 6 | 0 |
| 7 | -24 |
| 8 | -36 |
| 9 | -8 |
| 10 | 0 |
| 11 | 120 |
| 12 | 300 |
| 13 | 144 |
| 14 | 16 |
| 15 | 0 |
| 16 | -720 |
| 17 | -2640 |
| 18 | -2040 |
| 19 | -480 |
| 20 | -32 |
| 21 | 0 |
| 22 | 5040 |
| 23 | 25200 |
| 24 | 27720 |
| 25 | 10320 |
| 26 | 1440 |
| 27 | 64 |
| 28 | 0 |
| 29 | -40320 |
| 30 | -262080 |
| 31 | -383040 |
| 32 | -199920 |
| 33 | -43680 |
| 34 | -4032 |
| 35 | -128 |
| 36 | 0 |
| 37 | 362880 |
| 38 | 2963520 |
| 39 | 5503680 |
| 40 | 3764880 |
| 41 | 1142400 |
| 42 | 163968 |
| 43 | 10752 |
| 44 | 256 |
| 45 | 0 |
| 46 | -3628800 |
| 47 | -36288000 |
| 48 | -82978560 |