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 | 0 |
| 3 | 27 |
| 4 | -18 |
| 5 | -63 |
| 6 | 36 |
| 7 | 207 |
| 8 | -126 |
| 9 | -603 |
| 10 | 360 |
| 11 | 1827 |
| 12 | -1098 |
| 13 | -5463 |
| 14 | 3276 |
| 15 | 16407 |
| 16 | -9846 |
| 17 | -49203 |
| 18 | 29520 |
| 19 | 147627 |
| 20 | -88578 |
| 21 | -442863 |
| 22 | 265716 |
| 23 | 1328607 |
| 24 | -797166 |
| 25 | -3985803 |
| 26 | 2391480 |
| 27 | 11957427 |
| 28 | -7174458 |
| 29 | -35872263 |
| 30 | 21523356 |
| 31 | 107616807 |
| 32 | -64570086 |
| 33 | -322850403 |
| 34 | 193710240 |