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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 1 |
| 8 | 18 |
| 9 | 59 |
| 10 | 630 |
| 11 | 1681 |
| 12 | 28866 |
| 13 | 60083 |
| 14 | 757576 |
| 15 | 3514504 |
| 16 | 21423984 |
| 17 | 64372109 |
| 18 | 1024999170 |
| 19 | 2026631203 |
| 20 | 26920954613 |
| 21 | 105501588414 |
| 22 | 742299897060 |
| 23 | 1974251382095 |
| 24 | 31721456288956 |
| 25 | 74052852505684 |