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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 2 |
| 6 | 4 |
| 7 | 47 |
| 8 | 6 |
| 9 | 6 |
| 10 | 462 |
| 11 | 372 |
| 12 | 1589 |
| 13 | 20896 |
| 14 | 4118 |
| 15 | 12815 |
| 16 | 130528 |
| 17 | 1942045 |
| 18 | 163775 |
| 19 | 18340336 |
| 20 | 5065878 |
| 21 | 3607762 |