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 | 1 |
| 3 | 2 |
| 4 | 15 |
| 5 | 50 |
| 6 | 874 |
| 7 | 3515 |
| 8 | 94638 |
| 9 | 634630 |
| 10 | 18368060 |
| 11 | 149965474 |
| 12 | 7392944314 |
| 13 | 61596293433 |
| 14 | 4042125261152 |
| 15 | 46326163964879 |
| 16 | 4045711099761347 |
| 17 | 47868661342996788 |
| 18 | 6066544790946772416 |