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 | 40 |
| 2 | 718 |
| 3 | -41840 |
| 4 | -3573428 |
| 5 | 4674400 |
| 6 | 15945793480 |
| 7 | 613094814400 |
| 8 | -73925536369520 |
| 9 | -7283018465187200 |
| 10 | 295500169093761760 |
| 11 | 76056229626701574400 |
| 12 | 175306544520386380480 |
| 13 | -797966872588194008230400 |
| 14 | -33928739742998510567799680 |
| 15 | 8496145352999079190916992000 |