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 | 2 |
| 2 | 84 |
| 3 | 10800 |
| 4 | 2857680 |
| 5 | 1285956000 |
| 6 | 880599202560 |
| 7 | 853262368358400 |
| 8 | 1111400775560275200 |
| 9 | 1873276460474747328000 |
| 10 | 3967400888465895264384000 |
| 11 | 10313998054713896966296473600 |
| 12 | 32291970618091110826769565696000 |
| 13 | 119851615755915509174015455948800000 |