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 | 0 |
| 1 | 0 |
| 2 | 2 |
| 3 | 4 |
| 4 | 9 |
| 5 | 20 |
| 6 | 54 |
| 7 | 131 |
| 8 | 354 |
| 9 | 912 |
| 10 | 2457 |
| 11 | 6429 |
| 12 | 17081 |
| 13 | 44850 |
| 14 | 118578 |
| 15 | 311471 |