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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 14 |
| 6 | 43 |
| 7 | 138 |
| 8 | 455 |
| 9 | 1540 |
| 10 | 5305 |
| 11 | 18546 |
| 12 | 65616 |
| 13 | 234546 |
| 14 | 845683 |
| 15 | 3072350 |
| 16 | 11235393 |
| 17 | 41326470 |
| 18 | 152793376 |
| 19 | 567518950 |
| 20 | 2116666670 |
| 21 | 7924062430 |
| 22 | 29765741831 |
| 23 | 112157686170 |
| 24 | 423809991041 |
| 25 | 1605622028100 |
| 26 | 6097575361683 |
| 27 | 23207825593664 |
| 28 | 88512641860558 |