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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 18 |
| 5 | 116 |
| 6 | 627 |
| 7 | 6211 |
| 8 | 59011 |
| 9 | 449824 |
| 10 | 5256100 |
| 11 | 90734544 |
| 12 | 1163859524 |
| 13 | 24333174896 |
| 14 | 578216191424 |
| 15 | 11292787466976 |