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 | 48 |
| 3 | 648 |
| 4 | 3840 |
| 5 | 15000 |
| 6 | 45360 |
| 7 | 115248 |
| 8 | 258048 |
| 9 | 524880 |
| 10 | 990000 |
| 11 | 1756920 |
| 12 | 2965248 |
| 13 | 4798248 |
| 14 | 7491120 |
| 15 | 11340000 |
| 16 | 16711680 |
| 17 | 24054048 |
| 18 | 33907248 |
| 19 | 46915560 |
| 20 | 63840000 |
| 21 | 85571640 |
| 22 | 113145648 |
| 23 | 147756048 |
| 24 | 190771200 |
| 25 | 243750000 |
| 26 | 308458800 |
| 27 | 386889048 |
| 28 | 481275648 |