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) |
|---|---|
| 4 | 0 |
| 5 | 5 |
| 6 | 156 |
| 7 | 2114 |
| 8 | 19328 |
| 9 | 140571 |
| 10 | 882340 |
| 11 | 5007112 |
| 12 | 26441856 |
| 13 | 132439905 |
| 14 | 637468300 |
| 15 | 2976161790 |
| 16 | 13569454592 |
| 17 | 60725449335 |
| 18 | 267757190100 |
| 19 | 1166662948900 |
| 20 | 5034645823680 |
| 21 | 21556696454685 |
| 22 | 91704869986620 |
| 23 | 388044105102650 |
| 24 | 1634678955350400 |
| 25 | 6860481786528275 |
| 26 | 28700914012807556 |