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 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 65 |
| 6 | 292 |
| 7 | 1434 |
| 8 | 7875 |
| 9 | 47098 |
| 10 | 305226 |
| 11 | 2122983 |
| 12 | 15752080 |
| 13 | 124015310 |
| 14 | 1031857395 |
| 15 | 9041908204 |
| 16 | 83186138212 |
| 17 | 801235247145 |
| 18 | 8059220936672 |
| 19 | 84463182889321 |