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 | 2 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 24 |
| 5 | 24 |
| 6 | -20 |
| 7 | 0 |
| 8 | 366 |
| 9 | 324 |
| 10 | -42 |
| 11 | -312 |
| 12 | 4788 |
| 13 | 6036 |
| 14 | -1356 |
| 15 | -1820 |
| 16 | 54036 |
| 17 | 99252 |
| 18 | -3024 |
| 19 | -53352 |
| 20 | 686988 |
| 21 | 1382336 |
| 22 | 285870 |
| 23 | -926172 |
| 24 | 7988984 |
| 25 | 19975392 |
| 26 | 6245886 |
| 27 | -12161464 |
| 28 | 89970804 |
| 29 | 273568968 |
| 30 | 134393334 |
| 31 | -181279824 |