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 | 5 |
| 2 | 21 |
| 3 | 93 |
| 4 | 409 |
| 5 | 1837 |
| 6 | 8209 |
| 7 | 36969 |
| 8 | 166041 |
| 9 | 748889 |
| 10 | 3373941 |
| 11 | 15248153 |
| 12 | 68840633 |