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 | 2 |
| 2 | 5 |
| 3 | 15 |
| 4 | 54 |
| 5 | 216 |
| 6 | 947 |
| 7 | 4375 |
| 8 | 21018 |
| 9 | 103550 |
| 10 | 520041 |
| 11 | 2649391 |
| 12 | 13655190 |
| 13 | 71053780 |
| 14 | 372727751 |
| 15 | 1968880111 |
| 16 | 10463765490 |
| 17 | 55909445082 |
| 18 | 300160457453 |
| 19 | 1618364548591 |
| 20 | 8759315367894 |
| 21 | 47574840887024 |
| 22 | 259215969470139 |
| 23 | 1416461749625543 |
| 24 | 7760734001872842 |
| 25 | 42624971709868054 |