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 | 10 |
| 4 | 46 |
| 5 | 343 |
| 6 | 3248 |
| 7 | 42331 |
| 8 | 646029 |
| 9 | 12283531 |
| 10 | 300369796 |
| 11 | 8028643010 |
| 12 | 259488750744 |
| 13 | 9414916809095 |
| 14 | 362597750396740 |
| 15 | 15397728527812858 |
| 16 | 742238179058722891 |
| 17 | 40068968501510691894 |
| 18 | 2251262473052300960826 |
| 19 | 139566579945945392719413 |