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 | 6 |
| 2 | 37 |
| 3 | 235 |
| 4 | 1540 |
| 5 | 10427 |
| 6 | 73013 |
| 7 | 529032 |
| 8 | 3967195 |
| 9 | 30785747 |
| 10 | 247126450 |
| 11 | 2050937445 |
| 12 | 17585497797 |
| 13 | 155666739742 |
| 14 | 1421428484337 |
| 15 | 13377704321695 |
| 16 | 129659127547372 |
| 17 | 1293095848212799 |
| 18 | 13259069937250169 |
| 19 | 139671750579429512 |
| 20 | 1510382932875294447 |
| 21 | 16754464511605466311 |