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 | 6 |
| 3 | -36 |
| 4 | -216 |
| 5 | 1296 |
| 6 | -5184 |
| 7 | -145152 |
| 8 | -3856896 |
| 9 | -170325504 |
| 10 | -6133211136 |
| 11 | 1094593056768 |
| 12 | 26742290558976 |
| 13 | -497681937801216 |
| 14 | -14357497419546624 |
| 15 | 657148066947072000 |
| 16 | 12008320398059765760 |
| 17 | 1322255096225695531008 |
| 18 | 70546799432003423698944 |
| 19 | -6537119853797882157072384 |
| 20 | -27940593871362459110473728 |