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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 2 |
| 5 | 12 |
| 6 | 12 |
| 7 | 360 |
| 8 | 360 |
| 9 | 720 |
| 10 | 720 |
| 11 | 151200 |
| 12 | 151200 |
| 13 | 349272000 |
| 14 | 349272000 |
| 15 | 349272000 |
| 16 | 349272000 |
| 17 | 10488638160000 |
| 18 | 10488638160000 |
| 19 | 5354554667061600000 |
| 20 | 5354554667061600000 |
| 21 | 5354554667061600000 |
| 22 | 5354554667061600000 |