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 | 2 |
| 3 | 6 |
| 4 | 23 |
| 5 | 104 |
| 6 | 535 |
| 7 | 3081 |
| 8 | 19737 |
| 9 | 140454 |
| 10 | 1111136 |
| 11 | 9777465 |
| 12 | 95587370 |
| 13 | 1034517225 |
| 14 | 12324487009 |
| 15 | 160503772329 |