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 | 6 |
| 5 | 15 |
| 6 | 68 |
| 7 | 310 |
| 8 | 2096 |
| 9 | 16554 |
| 10 | 152497 |
| 11 | 1574652 |
| 12 | 17947667 |
| 13 | 223013311 |