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 | 3 |
| 3 | 12 |
| 4 | 56 |
| 5 | 288 |
| 6 | 1584 |
| 7 | 9153 |
| 8 | 54940 |
| 9 | 339937 |
| 10 | 2156457 |
| 11 | 13970079 |
| 12 | 92147905 |
| 13 | 617468715 |
| 14 | 4195848863 |
| 15 | 28873188732 |
| 16 | 200982289554 |
| 17 | 1413914236788 |
| 18 | 10045715705912 |
| 19 | 72041560145703 |
| 20 | 521233406146366 |
| 21 | 3803409400869139 |
| 22 | 27982484503275869 |
| 23 | 207531162828185908 |
| 24 | 1551323994123301229 |