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 | 0 |
| 3 | 0 |
| 4 | 9 |
| 5 | 20 |
| 6 | 96 |
| 7 | 656 |
| 8 | 5584 |
| 9 | 48913 |
| 10 | 494264 |
| 11 | 5383552 |
| 12 | 65103875 |
| 13 | 840566080 |
| 14 | 11834159652 |
| 15 | 176621049784 |
| 16 | 2838040416201 |
| 17 | 48060623405312 |