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 | 1 |
| 3 | -357 |
| 4 | -6999 |
| 5 | -62997 |
| 6 | 444529 |
| 7 | 27783003 |
| 8 | 508019689 |
| 9 | 3206511003 |
| 10 | -89889084999 |
| 11 | -3274278527517 |
| 12 | -49395223500999 |
| 13 | -66079827133317 |
| 14 | 16197028704290001 |
| 15 | 433384098559415643 |
| 16 | 4988878584849669609 |
| 17 | -35687369703800052357 |
| 18 | -2815548294132454060151 |
| 19 | -58942279760573467233357 |