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 | 2 |
| 6 | 1 |
| 7 | 10 |
| 8 | 47 |
| 9 | 350 |
| 10 | 3005 |
| 11 | 28722 |
| 12 | 302519 |
| 13 | 3471738 |
| 14 | 43181993 |
| 15 | 578730766 |
| 16 | 8317664191 |
| 17 | 127644961618 |
| 18 | 2083638325661 |
| 19 | 36055062511490 |
| 20 | 659316772258655 |
| 21 | 12705552903848466 |
| 22 | 257373902883624297 |
| 23 | 5467702595346969530 |
| 24 | 121562217391867941767 |