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 | 33 |
| 3 | 75 |
| 4 | 1305 |
| 5 | -8253 |
| 6 | -340711 |
| 7 | -2173509 |
| 8 | -758532375 |
| 9 | -3823240245 |
| 10 | -73518428511 |
| 11 | -342444310533 |
| 12 | -24952606638687 |
| 13 | -111735599023125 |
| 14 | -1975318542049815 |
| 15 | -8639356601706213 |
| 16 | -9590905885722547959 |
| 17 | -41296955508208952901 |
| 18 | -707029904720030040775 |
| 19 | -3010762771187568788685 |