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 | 1 |
| 3 | 2 |
| 4 | 8 |
| 5 | 52 |
| 6 | 502 |
| 7 | 6824 |
| 8 | 127166 |
| 9 | 3205924 |
| 10 | 108975934 |
| 11 | 5006366048 |
| 12 | 312601245662 |
| 13 | 26708244267148 |
| 14 | 3142852107059758 |
| 15 | 512229404374936616 |
| 16 | 116165284523764481294 |
| 17 | 36791597841822774872116 |
| 18 | 16320947226945992981680606 |
| 19 | 10163558457757761048966068912 |