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 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 8 |
| 5 | 28 |
| 6 | 107 |
| 7 | 418 |
| 8 | 1676 |
| 9 | 6848 |
| 10 | 28418 |
| 11 | 119444 |
| 12 | 507440 |
| 13 | 2175500 |
| 14 | 9400207 |
| 15 | 40895602 |
| 16 | 178984212 |
| 17 | 787503168 |
| 18 | 3481278734 |
| 19 | 15454765948 |
| 20 | 68871993872 |
| 21 | 307981243608 |
| 22 | 1381569997998 |
| 23 | 6215433403188 |
| 24 | 28036071086296 |