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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 5 |
| 6 | 21 |
| 7 | 127 |
| 8 | 618 |
| 9 | 2934 |
| 10 | 13542 |
| 11 | 61803 |
| 12 | 276650 |
| 13 | 1219508 |
| 14 | 5309179 |
| 15 | 22868295 |
| 16 | 97663066 |
| 17 | 414156142 |
| 18 | 1746438478 |