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 | 7 |
| 3 | 63 |
| 4 | 756 |
| 5 | 9716 |
| 6 | 132062 |
| 7 | 1865626 |
| 8 | 27124049 |
| 9 | 403197584 |
| 10 | 6100155272 |
| 11 | 93626517858 |
| 12 | 1454221328232 |
| 13 | 22815183746508 |
| 14 | 361030984965596 |
| 15 | 5755543515895284 |
| 16 | 92350704790963431 |
| 17 | 1490287557170676816 |
| 18 | 24171116970619575559 |
| 19 | 393808998160695560841 |
| 20 | 6442255541764422795759 |