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 | 7 |
| 2 | 43 |
| 3 | 4167 |
| 4 | 857143 |
| 5 | 909091 |
| 6 | 1443299 |
| 7 | 4166667 |
| 8 | 92857143 |
| 9 | 2205882353 |
| 10 | 2792792793 |
| 11 | 1046511627907 |
| 12 | 5737704918033 |
| 13 | 19083969465649 |
| 14 | 53947368421053 |
| 15 | 55882352941177 |
| 16 | 772727272727273 |
| 17 | 2962962962962962963 |
| 18 | 5806451612903225807 |
| 19 | 263888888888888888889 |