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 | 5 |
| 4 | 14 |
| 5 | 42 |
| 6 | 132 |
| 7 | 421 |
| 8 | 1382 |
| 9 | 4478 |
| 10 | 15580 |
| 11 | 54114 |
| 12 | 181676 |
| 13 | 650484 |
| 14 | 2289320 |
| 15 | 8028901 |
| 16 | 28045302 |
| 17 | 103229014 |
| 18 | 372640460 |
| 19 | 1336511110 |
| 20 | 4882492452 |
| 21 | 17534836812 |
| 22 | 63692926552 |
| 23 | 234287550818 |
| 24 | 868236370364 |
| 25 | 3281589811404 |