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 | 22 |
| 3 | 140 |
| 4 | 838 |
| 5 | 5092 |
| 6 | 29680 |
| 7 | 183220 |
| 8 | 1061814 |
| 9 | 6630116 |
| 10 | 39048472 |
| 11 | 242647660 |
| 12 | 1438692856 |
| 13 | 8910239756 |
| 14 | 53090781836 |
| 15 | 327214611580 |
| 16 | 1954347351734 |
| 17 | 11998820896676 |
| 18 | 71771002591048 |
| 19 | 439163289580348 |
| 20 | 2629051988484048 |