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 | -3 |
| 2 | 3 |
| 3 | 18 |
| 4 | -57 |
| 5 | -138 |
| 6 | 246 |
| 7 | 4281 |
| 8 | 13383 |
| 9 | -156906 |
| 10 | -450822 |
| 11 | -957729 |
| 12 | 23375886 |
| 13 | 289894875 |
| 14 | -179027895 |
| 15 | -3403581357 |
| 16 | -174968380137 |
| 17 | -419588974650 |
| 18 | 4439383168602 |
| 19 | 50400469832883 |
| 20 | 1027067921064738 |
| 21 | 428364930324489 |
| 22 | -18456487538087145 |
| 23 | -1019962180000311267 |