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 | 1 |
| 2 | -1 |
| 3 | 2 |
| 4 | 2 |
| 5 | -6 |
| 6 | 5 |
| 7 | -6 |
| 8 | 22 |
| 9 | -30 |
| 10 | 15 |
| 11 | 24 |
| 12 | -100 |
| 13 | 175 |
| 14 | -150 |
| 15 | 52 |
| 16 | -120 |
| 17 | 548 |
| 18 | -1125 |
| 19 | 1275 |
| 20 | -780 |
| 21 | 203 |
| 22 | 720 |
| 23 | -3528 |
| 24 | 8120 |
| 25 | -11025 |
| 26 | 9100 |
| 27 | -4263 |
| 28 | 877 |
| 29 | -5040 |
| 30 | 26136 |
| 31 | -65660 |
| 32 | 101535 |
| 33 | -101920 |
| 34 | 65366 |
| 35 | -24556 |
| 36 | 4140 |
| 37 | 40320 |
| 38 | -219168 |
| 39 | 590620 |
| 40 | -1009260 |
| 41 | 1167348 |
| 42 | -920808 |
| 43 | 478842 |
| 44 | -149040 |
| 45 | 21147 |