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 | 3 |
| 2 | 7 |
| 3 | 18 |
| 4 | 40 |
| 5 | 86 |
| 6 | 170 |
| 7 | 350 |
| 8 | 688 |
| 9 | 1394 |
| 10 | 2702 |
| 11 | 5338 |
| 12 | 10278 |
| 13 | 20078 |
| 14 | 38578 |
| 15 | 74820 |
| 16 | 143496 |
| 17 | 276890 |
| 18 | 530626 |
| 19 | 1020774 |
| 20 | 1955400 |
| 21 | 3754560 |
| 22 | 7190520 |
| 23 | 13790666 |
| 24 | 26407852 |
| 25 | 50612412 |
| 26 | 96911566 |
| 27 | 185660272 |
| 28 | 355485362 |
| 29 | 680860212 |
| 30 | 1303623528 |
| 31 | 2496462996 |