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 | 30 |
| 6 | 30 |
| 7 | 84 |
| 8 | 120 |
| 9 | 1260 |
| 10 | 840 |
| 11 | 13860 |
| 12 | 13860 |
| 13 | 180180 |
| 14 | 180180 |
| 15 | 180180 |
| 16 | 240240 |
| 17 | 6126120 |
| 18 | 6126120 |
| 19 | 116396280 |
| 20 | 58198140 |
| 21 | 116396280 |
| 22 | 116396280 |
| 23 | 2677114440 |
| 24 | 2677114440 |
| 25 | 13385572200 |
| 26 | 13385572200 |
| 27 | 40156716600 |
| 28 | 40156716600 |
| 29 | 776363187600 |
| 30 | 776363187600 |