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 | 3 |
| 6 | 0 |
| 7 | 13 |
| 8 | 64 |
| 9 | 235 |
| 10 | 1296 |
| 11 | 7013 |
| 12 | 41782 |
| 13 | 253420 |
| 14 | 1607418 |
| 15 | 10520883 |
| 16 | 70785653 |
| 17 | 488096844 |