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 | 3 |
| 5 | 44 |
| 6 | 175 |
| 7 | 1434 |
| 8 | 12313 |
| 9 | 59912 |
| 10 | 1057761 |
| 11 | 9211850 |
| 12 | 118785931 |
| 13 | 1702959972 |
| 14 | 21390805423 |
| 15 | 339381890834 |
| 16 | 4027183717425 |
| 17 | 89818053205904 |
| 18 | 1477419923299393 |
| 19 | 28377482210884242 |
| 20 | 608128083110593171 |
| 21 | 11954214606663753500 |
| 22 | 269933818505222203311 |