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 | 0 |
| 1 | -1 |
| 2 | -9 |
| 3 | -36 |
| 4 | -123 |
| 5 | -364 |
| 6 | -979 |
| 7 | -2380 |
| 8 | -5043 |
| 9 | -7884 |
| 10 | 717 |
| 11 | 84788 |
| 12 | 541901 |
| 13 | 2659124 |
| 14 | 11807949 |
| 15 | 49984308 |
| 16 | 206326989 |
| 17 | 839988020 |
| 18 | 3393375437 |
| 19 | 13648999220 |
| 20 | 54765341901 |
| 21 | 219438854964 |
| 22 | 878592183501 |
| 23 | 3516214227764 |