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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 19 |
| 5 | 63 |
| 6 | 216 |
| 7 | 756 |
| 8 | 2685 |
| 9 | 9650 |
| 10 | 35018 |
| 11 | 128084 |
| 12 | 471623 |
| 13 | 1746492 |
| 14 | 6499356 |
| 15 | 24290272 |
| 16 | 91123171 |
| 17 | 342984175 |
| 18 | 1294829776 |
| 19 | 4901319978 |
| 20 | 18597856445 |
| 21 | 70723784744 |
| 22 | 269486503694 |
| 23 | 1028736811230 |
| 24 | 3933715966653 |