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 | -2 |
| 3 | 24 |
| 4 | 60 |
| 5 | 245 |
| 6 | 642 |
| 7 | 1365 |
| 8 | 2552 |
| 9 | 5094 |
| 10 | -92010 |
| 11 | -147752 |
| 12 | -476940 |
| 13 | -1083134 |
| 14 | -2645230 |
| 15 | -5251515 |
| 16 | -10399760 |
| 17 | -18340246 |
| 18 | -33854778 |
| 19 | -56744526 |
| 20 | -95736020 |
| 21 | 1650319440 |
| 22 | 2252563082 |
| 23 | 6443314668 |
| 24 | 13202694120 |
| 25 | 29698078100 |
| 26 | 55023636486 |
| 27 | 113357565936 |