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 | 362880 |
| 10 | 3628800 |
| 11 | 39916800 |
| 12 | 402796800 |
| 13 | 3770686080 |
| 14 | 33187593600 |
| 15 | 278598101040 |
| 16 | 2261952938160 |
| 17 | 17986137205800 |
| 18 | 141564484858104 |
| 19 | 1112444773251726 |
| 20 | 8787513806478134 |
| 21 | 70146437009397871 |
| 22 | 568128719132038153 |
| 23 | 4647312969412825372 |