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 | 1 |
| 1 | 0 |
| 2 | -9 |
| 3 | 10 |
| 4 | 45 |
| 5 | -108 |
| 6 | -125 |
| 7 | 702 |
| 8 | -135 |
| 9 | -3320 |
| 10 | 4239 |
| 11 | 11250 |
| 12 | -31931 |
| 13 | -18180 |
| 14 | 165915 |
| 15 | -92762 |
| 16 | -651375 |
| 17 | 1101168 |
| 18 | 1747495 |
| 19 | -6710310 |
| 20 | -694179 |
| 21 | 30182500 |
| 22 | -28394829 |
| 23 | -101934450 |
| 24 | 229069225 |
| 25 | 203510232 |
| 26 | -1198850625 |
| 27 | 364506562 |
| 28 | 4767453045 |