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 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 80 |
| 5 | 238 |
| 6 | 723 |
| 7 | 2183 |
| 8 | 5653 |
| 9 | 19674 |
| 10 | 59042 |
| 11 | 177145 |
| 12 | 531429 |
| 13 | 1594313 |
| 14 | 4782955 |
| 15 | 14348892 |
| 16 | 43046708 |
| 17 | 129140146 |
| 18 | 387420471 |
| 19 | 1162261451 |
| 20 | 3486784397 |
| 21 | 10460353182 |
| 22 | 31381059590 |
| 23 | 94143178804 |
| 24 | 282429536457 |
| 25 | 847288609421 |