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 | 2 |
| 2 | 14 |
| 3 | 74 |
| 4 | 352 |
| 5 | 1588 |
| 6 | 6946 |
| 7 | 29786 |
| 8 | 126008 |
| 9 | 527900 |
| 10 | 2195580 |
| 11 | 9080772 |
| 12 | 37392864 |
| 13 | 153434536 |
| 14 | 627778954 |
| 15 | 2562441466 |
| 16 | 10438340104 |
| 17 | 42449348236 |
| 18 | 172376641924 |
| 19 | 699100282156 |
| 20 | 2832205421824 |
| 21 | 11462854280536 |
| 22 | 46354571222164 |