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 | 33022080 |
| 12 | 277280640 |
| 13 | 2184341040 |
| 14 | 16427628720 |
| 15 | 119892387720 |
| 16 | 861175365144 |
| 17 | 6157828055310 |
| 18 | 44222780245622 |
| 19 | 321113303226243 |
| 20 | 2369364111428885 |
| 21 | 17667206334000068 |
| 22 | 132553643382927196 |
| 23 | 997400200347756816 |