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 | 2 |
| 2 | 5 |
| 3 | 10 |
| 4 | 22 |
| 5 | 44 |
| 6 | 90 |
| 7 | 180 |
| 8 | 362 |
| 9 | 724 |
| 10 | 1450 |
| 11 | 2900 |
| 12 | 5802 |
| 13 | 11604 |
| 14 | 23210 |
| 15 | 46420 |
| 16 | 92842 |
| 17 | 185684 |
| 18 | 371370 |
| 19 | 742740 |
| 20 | 1485482 |
| 21 | 2970964 |
| 22 | 5941930 |
| 23 | 11883860 |
| 24 | 23767722 |
| 25 | 47535444 |
| 26 | 95070890 |
| 27 | 190141780 |
| 28 | 380283562 |
| 29 | 760567124 |
| 30 | 1521134250 |