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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 24 |
| 4 | 211 |
| 5 | 2325 |
| 6 | 30198 |
| 7 | 452809 |
| 8 | 7695777 |
| 9 | 146193678 |
| 10 | 3069668575 |
| 11 | 70595504859 |
| 12 | 1764755571192 |
| 13 | 47645601726541 |
| 14 | 1381657584006399 |
| 15 | 42829752879449400 |
| 16 | 1413337528735664887 |
| 17 | 49465522112961344241 |
| 18 | 1830184115528550306438 |
| 19 | 71375848864779552073957 |