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) |
|---|---|
| 2 | 2 |
| 3 | 18 |
| 4 | 133 |
| 5 | 873 |
| 6 | 5182 |
| 7 | 27786 |
| 8 | 135370 |
| 9 | 602454 |
| 10 | 2466628 |
| 11 | 9358497 |
| 12 | 33134431 |
| 13 | 110184932 |
| 14 | 346141949 |
| 15 | 1032550097 |
| 16 | 2938104492 |
| 17 | 8006865684 |
| 18 | 20971632456 |
| 19 | 52958252851 |
| 20 | 129291697111 |
| 21 | 305924724070 |
| 22 | 703108665327 |
| 23 | 1572722761341 |