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 | 9 |
| 4 | 41 |
| 5 | 248 |
| 6 | 1610 |
| 7 | 11065 |
| 8 | 78218 |
| 9 | 563675 |
| 10 | 4113988 |
| 11 | 30329616 |
| 12 | 225394071 |
| 13 | 1686227909 |