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 | 14 |
| 3 | -57 |
| 4 | 246 |
| 5 | -1038 |
| 6 | 4424 |
| 7 | -18777 |
| 8 | 79846 |
| 9 | -339258 |
| 10 | 1442004 |
| 11 | -6128202 |
| 12 | 26045436 |
| 13 | -110691948 |
| 14 | 470442924 |
| 15 | -1999378137 |
| 16 | 8497365126 |
| 17 | -36113785698 |
| 18 | 153483619604 |
| 19 | -652305322542 |
| 20 | 2772297736276 |
| 21 | -11782265148228 |
| 22 | 50074627320864 |
| 23 | -212817165231882 |
| 24 | 904472953925596 |