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 | 4 |
| 2 | -1442 |
| 3 | -17432 |
| 4 | 6237580 |
| 5 | 126613744 |
| 6 | -44965503224 |
| 7 | -1287479045408 |
| 8 | 453768009722512 |
| 9 | 16832227624528960 |
| 10 | -5887014913080686624 |
| 11 | -268961938417954983296 |
| 12 | 93340097422316232142528 |
| 13 | 5079118464249805316316928 |
| 14 | -1748851732685582642764208000 |