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 | 5 |
| 3 | 24 |
| 4 | 105 |
| 5 | 451 |
| 6 | 1920 |
| 7 | 8149 |
| 8 | 34545 |
| 9 | 146376 |
| 10 | 620125 |
| 11 | 2626999 |
| 12 | 11128320 |
| 13 | 47140601 |
| 14 | 199691245 |
| 15 | 845906424 |
| 16 | 3583318305 |
| 17 | 15179181851 |
| 18 | 64300049280 |
| 19 | 272379384749 |
| 20 | 1153817597625 |
| 21 | 4887649790376 |
| 22 | 20704416783605 |
| 23 | 87705316964399 |
| 24 | 371525684705280 |
| 25 | 1573808055889201 |
| 26 | 6666757908429845 |