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) |
|---|---|
| 15 | 1 |
| 16 | -15 |
| 17 | 105 |
| 18 | -455 |
| 19 | 1350 |
| 20 | -2793 |
| 21 | 3625 |
| 22 | -765 |
| 23 | -9840 |
| 24 | 29120 |
| 25 | -48657 |
| 26 | 47370 |
| 27 | 1680 |
| 28 | -111060 |
| 29 | 252555 |
| 30 | -343526 |
| 31 | 267540 |
| 32 | 63210 |
| 33 | -623510 |
| 34 | 1216425 |
| 35 | -1495173 |
| 36 | 1093210 |
| 37 | 166425 |
| 38 | -2073645 |
| 39 | 3963260 |
| 40 | -4864839 |
| 41 | 3872295 |
| 42 | -618310 |
| 43 | -4345470 |
| 44 | 9477960 |
| 45 | -12611991 |