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 | 1 |
| 2 | 1 |
| 3 | -2 |
| 4 | -19 |
| 5 | -74 |
| 6 | -68 |
| 7 | 1856 |
| 8 | 22717 |
| 9 | 182806 |
| 10 | 1095506 |
| 11 | 2706452 |
| 12 | -62235754 |
| 13 | -1630900556 |
| 14 | -28213310474 |
| 15 | -422792067164 |
| 16 | -5747245586467 |
| 17 | -68720160772442 |
| 18 | -602550199498622 |
| 19 | 1056275553274100 |
| 20 | 251539588303778798 |
| 21 | 9237652624016037908 |
| 22 | 263685036472764512992 |