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 | 12 |
| 3 | 49 |
| 4 | 179 |
| 5 | 441 |
| 6 | -860 |
| 7 | -23634 |
| 8 | -229246 |
| 9 | -1705649 |
| 10 | -10757370 |
| 11 | -57800600 |
| 12 | -246084657 |
| 13 | -551185526 |
| 14 | 3612960360 |
| 15 | 66196180728 |
| 16 | 641858169138 |
| 17 | 4911870929096 |
| 18 | 31792139997384 |
| 19 | 172691510260794 |
| 20 | 711428107177975 |
| 21 | 1066704835555530 |
| 22 | -18659356513414560 |