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 | 20 |
| 6 | 47 |
| 7 | 112 |
| 8 | 279 |
| 9 | 712 |
| 10 | 1868 |
| 11 | 5020 |
| 12 | 13792 |
| 13 | 38630 |
| 14 | 110105 |
| 15 | 318756 |
| 16 | 935817 |
| 17 | 2782424 |
| 18 | 8368484 |
| 19 | 25434314 |
| 20 | 78047606 |