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 | 4 |
| 4 | 13 |
| 5 | 49 |
| 6 | 228 |
| 7 | 1034 |
| 8 | 5133 |
| 9 | 25710 |
| 10 | 133872 |
| 11 | 708976 |
| 12 | 3846150 |
| 13 | 21170077 |
| 14 | 118429072 |
| 15 | 670537495 |