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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 6 |
| 4 | 192 |
| 5 | 1620 |
| 6 | 7680 |
| 7 | 26250 |
| 8 | 72576 |
| 9 | 172872 |
| 10 | 368640 |
| 11 | 721710 |
| 12 | 1320000 |
| 13 | 2283996 |
| 14 | 3773952 |
| 15 | 5997810 |
| 16 | 9219840 |
| 17 | 13770000 |
| 18 | 20054016 |
| 19 | 28564182 |
| 20 | 39890880 |
| 21 | 54734820 |
| 22 | 73920000 |
| 23 | 98407386 |
| 24 | 129309312 |
| 25 | 167904600 |
| 26 | 215654400 |
| 27 | 274218750 |
| 28 | 345473856 |