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 | 3 |
| 2 | 2 |
| 3 | 6 |
| 4 | 13 |
| 5 | 43 |
| 6 | 125 |
| 7 | 442 |
| 8 | 1498 |
| 9 | 5393 |
| 10 | 19187 |
| 11 | 69186 |
| 12 | 248111 |
| 13 | 888783 |
| 14 | 3159624 |
| 15 | 11137858 |
| 16 | 38773614 |
| 17 | 132891874 |
| 18 | 446478045 |
| 19 | 1463990116 |
| 20 | 4662369227 |
| 21 | 14350218212 |