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) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 20 |
| 7 | 45 |
| 8 | 105 |
| 9 | 249 |
| 10 | 599 |
| 11 | 1463 |
| 12 | 3614 |
| 13 | 9016 |
| 14 | 22695 |
| 15 | 57564 |
| 16 | 146985 |
| 17 | 377555 |
| 18 | 974924 |
| 19 | 2529308 |
| 20 | 6589734 |
| 21 | 17234114 |
| 22 | 45228343 |
| 23 | 119069228 |
| 24 | 314368027 |
| 25 | 832193902 |
| 26 | 2208347917 |
| 27 | 5873364623 |
| 28 | 15653499416 |
| 29 | 41800070483 |
| 30 | 111821751649 |