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 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 8 |
| 8 | 19 |
| 9 | 64 |
| 10 | 225 |
| 11 | 928 |
| 12 | 3441 |
| 13 | 17536 |
| 14 | 79259 |
| 15 | 454016 |
| 16 | 2424195 |
| 17 | 15628288 |
| 18 | 94471089 |
| 19 | 679156224 |
| 20 | 4613520889 |
| 21 | 36563599360 |
| 22 | 275148653115 |