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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 3 |
| 7 | 8 |
| 8 | 19 |
| 9 | 41 |
| 10 | 85 |
| 11 | 174 |
| 12 | 352 |
| 13 | 708 |
| 14 | 1420 |
| 15 | 2844 |
| 16 | 5693 |
| 17 | 11391 |
| 18 | 22788 |
| 19 | 45583 |
| 20 | 91173 |
| 21 | 182353 |
| 22 | 364714 |
| 23 | 729436 |
| 24 | 1458880 |
| 25 | 2917768 |
| 26 | 5835544 |
| 27 | 11671097 |
| 28 | 23342203 |
| 29 | 46684416 |
| 30 | 93368843 |
| 31 | 186737697 |
| 32 | 373475405 |
| 33 | 746950822 |
| 34 | 1493901656 |
| 35 | 2987803324 |
| 36 | 5975606660 |
| 37 | 11951213332 |
| 38 | 23902426677 |
| 39 | 47804853367 |
| 40 | 95609706748 |