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) |
|---|---|
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 10 |
| 7 | 65 |
| 8 | 385 |
| 9 | 2345 |
| 10 | 15204 |
| 11 | 105880 |
| 12 | 793210 |
| 13 | 6382860 |
| 14 | 55020966 |
| 15 | 506505272 |
| 16 | 4963812035 |
| 17 | 51629528080 |
| 18 | 568303728360 |
| 19 | 6602266433920 |
| 20 | 80751432154868 |
| 21 | 1037402030622720 |
| 22 | 13968636570706370 |
| 23 | 196748236140538368 |
| 24 | 2893482720437769317 |
| 25 | 44355269272024284160 |