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 | -29 |
| 2 | 377 |
| 3 | -2900 |
| 4 | 14877 |
| 5 | -56666 |
| 6 | 189109 |
| 7 | -649339 |
| 8 | 2219834 |
| 9 | -6777677 |
| 10 | 19041980 |
| 11 | -54885893 |
| 12 | 159810358 |
| 13 | -432662339 |
| 14 | 1117635553 |
| 15 | -2957018205 |
| 16 | 7799355410 |
| 17 | -19555103564 |
| 18 | 48073453671 |
| 19 | -119774561120 |
| 20 | 294567447945 |