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 | 2 |
| 2 | 8 |
| 3 | 44 |
| 4 | 308 |
| 5 | 2660 |
| 6 | 27764 |
| 7 | 343604 |
| 8 | 4948196 |
| 9 | 81477188 |
| 10 | 1510645556 |
| 11 | 31133831540 |
| 12 | 705725536868 |
| 13 | 17441324917508 |
| 14 | 466571232425012 |
| 15 | 13427966856358196 |
| 16 | 413627214916715492 |
| 17 | 13576185998718106820 |
| 18 | 472963964292142718516 |
| 19 | 17429043637241263344116 |
| 20 | 677320641352700988657764 |