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 | 32 |
| 4 | 0 |
| 5 | 328 |
| 6 | 2976 |
| 7 | 25512 |
| 8 | 124352 |
| 9 | 758752 |
| 10 | 4852448 |
| 11 | 26735408 |
| 12 | 145945312 |
| 13 | 805129880 |
| 14 | 4334341216 |
| 15 | 22824469832 |
| 16 | 119276925152 |
| 17 | 617722010896 |
| 18 | 3163151197504 |
| 19 | 16059782780784 |
| 20 | 80965219241952 |
| 21 | 405344545960912 |