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 | 1 |
| 2 | 0 |
| 3 | -4 |
| 4 | -1 |
| 5 | 47 |
| 6 | 17 |
| 7 | -1111 |
| 8 | -12 |
| 9 | 43476 |
| 10 | -49665 |
| 11 | -2391805 |
| 12 | 7528897 |
| 13 | 168436465 |
| 14 | -1052303380 |
| 15 | -14234148280 |
| 16 | 161462347715 |
| 17 | 1288890088835 |
| 18 | -27585406164839 |
| 19 | -91839429007223 |
| 20 | 5125915000647712 |
| 21 | -6443738757309888 |
| 22 | -1013794188308572677 |
| 23 | 6728499674632962055 |
| 24 | 205866724424357904465 |