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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 66 |
| 4 | 795 |
| 5 | 16420 |
| 6 | 278564 |
| 7 | 5105373 |
| 8 | 90871494 |
| 9 | 1635675910 |
| 10 | 29316316535 |
| 11 | 526297607496 |
| 12 | 9442398055752 |
| 13 | 169448124595321 |
| 14 | 3040546683808010 |
| 15 | 54560921044808010 |
| 16 | 979052407236876819 |
| 17 | 17568407254504944748 |