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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 18 |
| 5 | 105 |
| 6 | 636 |
| 7 | 4710 |
| 8 | 38508 |
| 9 | 352902 |
| 10 | 3563297 |
| 11 | 39467081 |
| 12 | 475326930 |
| 13 | 6198134207 |
| 14 | 86912048471 |
| 15 | 1305146666727 |
| 16 | 20897040866280 |