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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 4 |
| 7 | 8 |
| 8 | 21 |
| 9 | 55 |
| 10 | 72 |
| 11 | 144 |
| 12 | 377 |
| 13 | 987 |
| 14 | 1292 |
| 15 | 2584 |
| 16 | 6765 |
| 17 | 17711 |
| 18 | 23184 |
| 19 | 46368 |
| 20 | 121393 |
| 21 | 317811 |
| 22 | 416020 |
| 23 | 832040 |
| 24 | 2178309 |
| 25 | 5702887 |
| 26 | 7465176 |