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 | 1 |
| 3 | 3 |
| 4 | 4 |
| 5 | 20 |
| 6 | 30 |
| 7 | 210 |
| 8 | 336 |
| 9 | 3024 |
| 10 | 5040 |
| 11 | 55440 |
| 12 | 95040 |
| 13 | 1235520 |
| 14 | 2162160 |
| 15 | 32432400 |
| 16 | 57657600 |
| 17 | 980179200 |
| 18 | 1764322560 |
| 19 | 33522128640 |
| 20 | 60949324800 |
| 21 | 1279935820800 |
| 22 | 2346549004800 |
| 23 | 53970627110400 |
| 24 | 99638080819200 |
| 25 | 2490952020480000 |
| 26 | 4626053752320000 |