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 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 21 |
| 5 | 131 |
| 6 | 914 |
| 7 | 6910 |
| 8 | 55477 |
| 9 | 466729 |
| 10 | 4076430 |
| 11 | 36712325 |
| 12 | 339195058 |
| 13 | 3202515525 |
| 14 | 30803440806 |
| 15 | 301094270964 |
| 16 | 2984903334517 |
| 17 | 29961600364523 |
| 18 | 304094354787062 |
| 19 | 3117138919265903 |
| 20 | 32238856059792302 |
| 21 | 336132907436386486 |
| 22 | 3530470987229030696 |
| 23 | 37330864330583904876 |
| 24 | 397168915877285183906 |