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 | 30 |
| 3 | -802 |
| 4 | 45414 |
| 5 | -4508190 |
| 6 | 692197470 |
| 7 | -151610017950 |
| 8 | 44827810930305 |
| 9 | -17193060505570335 |
| 10 | 8298004578522898140 |
| 11 | -4920774627129981351120 |
| 12 | 3516683319021255757053900 |
| 13 | -2980761698101283167670391780 |
| 14 | 2956463734237276273792194346560 |
| 15 | -3392220222832838757465019626175680 |