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 | 48 |
| 4 | -1040 |
| 5 | 62720 |
| 6 | -4314624 |
| 7 | 498003968 |
| 8 | -70081316864 |
| 9 | 13529482592256 |
| 10 | -3175495421788160 |
| 11 | 933402531586899968 |
| 12 | -326784893253162369024 |
| 13 | 136568449424117316190208 |
| 14 | -66517446960602151366164480 |