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 | 1 |
| 2 | 1 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 1 |
| 8 | 5 |
| 9 | 19 |
| 10 | 123 |
| 11 | 871 |
| 12 | 8304 |
| 13 | 92539 |
| 14 | 1210044 |
| 15 | 17860267 |
| 16 | 293210063 |
| 17 | 5277557739 |
| 18 | 103177250918 |
| 19 | 2174556695546 |