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 | 3 |
| 4 | 6 |
| 5 | 20 |
| 6 | 67 |
| 7 | 291 |
| 8 | 1099 |
| 9 | 5780 |
| 10 | 26249 |
| 11 | 153238 |
| 12 | 832366 |
| 13 | 5443440 |
| 14 | 32738738 |
| 15 | 239515824 |
| 16 | 1591963864 |
| 17 | 12548347149 |
| 18 | 93066370414 |