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 | 2 |
| 3 | 6 |
| 4 | 16 |
| 5 | 42 |
| 6 | 110 |
| 7 | 288 |
| 8 | 754 |
| 9 | 1974 |
| 10 | 5168 |
| 11 | 13530 |
| 12 | 35422 |
| 13 | 92736 |
| 14 | 242786 |
| 15 | 635622 |
| 16 | 1664080 |
| 17 | 4356618 |
| 18 | 11405774 |
| 19 | 29860704 |
| 20 | 78176338 |
| 21 | 204668310 |
| 22 | 535828592 |
| 23 | 1402817466 |
| 24 | 3672623806 |
| 25 | 9615053952 |
| 26 | 25172538050 |
| 27 | 65902560198 |
| 28 | 172535142544 |