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 | 1 |
| 3 | 3 |
| 4 | 20 |
| 5 | 35 |
| 6 | 126 |
| 7 | 231 |
| 8 | 3432 |
| 9 | 6435 |
| 10 | 24310 |
| 11 | 46189 |
| 12 | 352716 |
| 13 | 676039 |
| 14 | 2600150 |
| 15 | 5014575 |
| 16 | 155117520 |
| 17 | 300540195 |
| 18 | 1166803110 |
| 19 | 2268783825 |
| 20 | 17672631900 |
| 21 | 34461632205 |
| 22 | 134564468610 |
| 23 | 263012370465 |
| 24 | 4116715363800 |
| 25 | 8061900920775 |
| 26 | 31602651609438 |
| 27 | 61989816618513 |
| 28 | 486734856412028 |