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) |
|---|---|
| 6 | 1 |
| 7 | 0 |
| 8 | 15 |
| 9 | 80 |
| 10 | 493 |
| 11 | 5730 |
| 12 | 45790 |
| 13 | 501690 |
| 14 | 5747805 |
| 15 | 66738169 |
| 16 | 884847355 |
| 17 | 12032825028 |
| 18 | 174686734180 |
| 19 | 2698980641742 |
| 20 | 43470161714616 |
| 21 | 739558796434277 |
| 22 | 13161203468888236 |
| 23 | 244555222834161480 |