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 | 4 |
| 2 | 24 |
| 3 | 160 |
| 4 | 132 |
| 5 | 936 |
| 6 | 5700 |
| 7 | 720 |
| 8 | 5312 |
| 9 | 33264 |
| 10 | 198144 |
| 11 | 3940 |
| 12 | 29880 |
| 13 | 190980 |
| 14 | 1155600 |
| 15 | 6823620 |
| 16 | 21672 |
| 17 | 167712 |
| 18 | 1088856 |
| 19 | 6670656 |
| 20 | 39786120 |
| 21 | 233908896 |
| 22 | 119812 |
| 23 | 941640 |
| 24 | 6189540 |
| 25 | 38300976 |
| 26 | 230340740 |
| 27 | 1363667256 |
| 28 | 7997325700 |