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 | 510312 |
| 11 | 2691600 |
| 12 | 13794150 |
| 13 | 69309240 |
| 14 | 343501500 |
| 15 | 1686135376 |
| 16 | 8221437000 |
| 17 | 39901776360 |
| 18 | 193054016840 |
| 19 | 932142850800 |
| 20 | 4495236798162 |
| 21 | 21664357535320 |
| 22 | 104388120866100 |
| 23 | 503044634004000 |
| 24 | 2425003924383900 |
| 25 | 11696087875731624 |