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 | 1 |
| 5 | 2 |
| 6 | 7 |
| 7 | 29 |
| 8 | 147 |
| 9 | 883 |
| 10 | 6156 |
| 11 | 48942 |
| 12 | 437404 |
| 13 | 4343041 |
| 14 | 47444364 |
| 15 | 565601104 |
| 16 | 7307463941 |
| 17 | 101713884677 |
| 18 | 1517483769898 |
| 19 | 24157610375637 |
| 20 | 408751073418742 |
| 21 | 7325240566502843 |
| 22 | 138608292368966173 |
| 23 | 2761503816421313729 |
| 24 | 57782245813372891911 |
| 25 | 1266895493728240876072 |