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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 15 |
| 5 | 48 |
| 6 | 167 |
| 7 | 602 |
| 8 | 2256 |
| 9 | 8660 |
| 10 | 33958 |
| 11 | 135292 |
| 12 | 546422 |
| 13 | 2231462 |
| 14 | 9199869 |
| 15 | 38237213 |
| 16 | 160047496 |
| 17 | 674034147 |
| 18 | 2854137769 |
| 19 | 12144094756 |
| 20 | 51895919734 |
| 21 | 222634125803 |
| 22 | 958474338539 |
| 23 | 4139623680861 |
| 24 | 17931324678301 |
| 25 | 77880642231286 |
| 26 | 339093495674090 |
| 27 | 1479789701661116 |