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 | 6 |
| 2 | -542 |
| 3 | -10188 |
| 4 | 878700 |
| 5 | 28826856 |
| 6 | -2366481864 |
| 7 | -114170427792 |
| 8 | 8889763054992 |
| 9 | 581262636440160 |
| 10 | -42756971593427424 |
| 11 | -3616239868184689344 |
| 12 | 250151386181903425728 |
| 13 | 26583148042820425844352 |
| 14 | -1720138627513899785854080 |
| 15 | -225431665727586284647620864 |