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 | 4 |
| 3 | -12 |
| 4 | -2272 |
| 5 | -166960 |
| 6 | -13136448 |
| 7 | -1177426880 |
| 8 | -116571720704 |
| 9 | -11452654888704 |
| 10 | -669616618900480 |
| 11 | 214088681811547136 |
| 12 | 155062926684742508544 |
| 13 | 76744341986122463531008 |
| 14 | 36379718195920790292840448 |