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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 12 |
| 6 | 25 |
| 7 | 50 |
| 8 | 103 |
| 9 | 206 |
| 10 | 413 |
| 11 | 826 |
| 12 | 1654 |
| 13 | 3308 |
| 14 | 6617 |
| 15 | 13234 |
| 16 | 26472 |
| 17 | 52944 |
| 18 | 105889 |
| 19 | 211778 |
| 20 | 423558 |
| 21 | 847116 |
| 22 | 1694233 |
| 23 | 3388466 |
| 24 | 6776935 |
| 25 | 13553870 |
| 26 | 27107741 |
| 27 | 54215482 |
| 28 | 108430966 |
| 29 | 216861932 |
| 30 | 433723865 |
| 31 | 867447730 |