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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 24 |
| 6 | 300 |
| 7 | 2400 |
| 8 | 15750 |
| 9 | 92680 |
| 10 | 510288 |
| 11 | 2691600 |
| 12 | 13793850 |
| 13 | 69309240 |
| 14 | 343499100 |
| 15 | 1686135352 |
| 16 | 8221421250 |
| 17 | 39901776360 |
| 18 | 193053923860 |
| 19 | 932142850800 |
| 20 | 4495236287850 |
| 21 | 21664357532920 |
| 22 | 104388118174500 |
| 23 | 503044634004000 |
| 24 | 2425003910574000 |
| 25 | 11696087875731600 |