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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 6 |
| 6 | 23 |
| 7 | 112 |
| 8 | 801 |
| 9 | 7840 |
| 10 | 97723 |
| 11 | 1436873 |
| 12 | 23791155 |
| 13 | 432878091 |
| 14 | 8544173926 |
| 15 | 181519645163 |
| 16 | 4127569521160 |