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) |
|---|---|
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 1 |
| 7 | 5 |
| 8 | 19 |
| 9 | 112 |
| 10 | 828 |
| 11 | 7441 |
| 12 | 76579 |
| 13 | 871225 |
| 14 | 10809051 |
| 15 | 144730446 |
| 16 | 2079635889 |
| 17 | 31912025537 |
| 18 | 520913578812 |
| 19 | 9013780062785 |
| 20 | 164829273635749 |
| 21 | 3176388519597555 |
| 22 | 64343477504391475 |
| 23 | 1366925655386979893 |
| 24 | 30390554390984325019 |
| 25 | 705740995420852895453 |