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 | 8 |
| 3 | 21 |
| 4 | 54 |
| 5 | 137 |
| 6 | 344 |
| 7 | 857 |
| 8 | 2122 |
| 9 | 5229 |
| 10 | 12836 |
| 11 | 31413 |
| 12 | 76686 |
| 13 | 186833 |
| 14 | 454448 |
| 15 | 1103921 |
| 16 | 2678674 |
| 17 | 6494037 |
| 18 | 15732284 |
| 19 | 38089677 |
| 20 | 92173782 |
| 21 | 222961529 |
| 22 | 539145416 |
| 23 | 1303349513 |
| 24 | 3150038746 |
| 25 | 7611815613 |
| 26 | 18390447188 |
| 27 | 44426264421 |
| 28 | 107310084894 |