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 | 3 |
| 3 | 7 |
| 4 | 18 |
| 5 | 49 |
| 6 | 135 |
| 7 | 383 |
| 8 | 1104 |
| 9 | 3228 |
| 10 | 9554 |
| 11 | 28557 |
| 12 | 86095 |
| 13 | 261487 |
| 14 | 799323 |
| 15 | 2457327 |
| 16 | 7592620 |
| 17 | 23565444 |
| 18 | 73437284 |
| 19 | 229691620 |
| 20 | 720800824 |
| 21 | 2268820824 |
| 22 | 7161255962 |
| 23 | 22661307317 |
| 24 | 71878917199 |
| 25 | 228487568175 |
| 26 | 727779875401 |
| 27 | 2322485254421 |
| 28 | 7424488376794 |
| 29 | 23773398866825 |