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) |
|---|---|
| 1 | 3 |
| 2 | 4 |
| 3 | -24 |
| 4 | 5 |
| 5 | -70 |
| 6 | 210 |
| 7 | 6 |
| 8 | -96 |
| 9 | -48 |
| 10 | 960 |
| 11 | -1920 |
| 12 | 7 |
| 13 | -126 |
| 14 | -126 |
| 15 | 1386 |
| 16 | 1386 |
| 17 | -12012 |
| 18 | 18018 |
| 19 | 8 |
| 20 | -160 |
| 21 | -160 |
| 22 | 1920 |
| 23 | -80 |
| 24 | 3840 |
| 25 | -17920 |
| 26 | 640 |
| 27 | -26880 |
| 28 | 143360 |
| 29 | -172032 |
| 30 | 9 |
| 31 | -198 |
| 32 | -198 |
| 33 | 2574 |
| 34 | -198 |
| 35 | 5148 |
| 36 | -25740 |
| 37 | 2574 |
| 38 | 2574 |
| 39 | -77220 |
| 40 | 218790 |
| 41 | -25740 |
| 42 | 437580 |
| 43 | -1662804 |
| 44 | 1662804 |
| 45 | 10 |
| 46 | -240 |
| 47 | -240 |
| 48 | 3360 |
| 49 | -240 |
| 50 | 6720 |
| 51 | -35840 |
| 52 | -120 |
| 53 | 6720 |
| 54 | 3360 |