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 | 3 |
| 3 | 6 |
| 4 | 16 |
| 5 | 34 |
| 6 | 90 |
| 7 | 211 |
| 8 | 558 |
| 9 | 1430 |
| 10 | 3908 |
| 11 | 10725 |
| 12 | 30825 |
| 13 | 90156 |
| 14 | 273234 |
| 15 | 848355 |
| 16 | 2714399 |
| 17 | 8909057 |
| 18 | 30042866 |
| 19 | 103859678 |
| 20 | 368075596 |
| 21 | 1335537312 |
| 22 | 4958599228 |
| 23 | 18820993913 |
| 24 | 72980867400 |
| 25 | 288885080660 |
| 26 | 1166541823566 |
| 27 | 4802259167367 |
| 28 | 20141650236664 |