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 | 9 |
| 5 | 23 |
| 6 | 57 |
| 7 | 151 |
| 8 | 427 |
| 9 | 1263 |
| 10 | 3823 |
| 11 | 11724 |
| 12 | 36048 |
| 13 | 110953 |
| 14 | 342079 |
| 15 | 1064468 |
| 16 | 3341067 |
| 17 | 10583564 |
| 18 | 33727683 |
| 19 | 107931482 |
| 20 | 346615834 |