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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 5040 |
| 8 | 40320 |
| 9 | 362879 |
| 10 | 3628781 |
| 11 | 39916492 |
| 12 | 478996716 |
| 13 | 6226941864 |
| 14 | 87176969880 |
| 15 | 1307651304960 |
| 16 | 20922368987520 |
| 17 | 355679390626560 |
| 18 | 6402213152423659 |
| 19 | 121641748198554547 |
| 20 | 2432828930036156696 |
| 21 | 51089280818439941448 |
| 22 | 1123961390341566969192 |