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 | 3 |
| 5 | 6 |
| 6 | 12 |
| 7 | 21 |
| 8 | 34 |
| 9 | 69 |
| 10 | 140 |
| 11 | 278 |
| 12 | 561 |
| 13 | 1144 |
| 14 | 2367 |
| 15 | 4936 |
| 16 | 9503 |
| 17 | 19368 |
| 18 | 38202 |
| 19 | 77911 |
| 20 | 156458 |
| 21 | 318911 |
| 22 | 651462 |
| 23 | 1329624 |
| 24 | 2596458 |
| 25 | 5144833 |
| 26 | 10494839 |
| 27 | 20500025 |
| 28 | 40923643 |
| 29 | 83620258 |
| 30 | 164982516 |
| 31 | 335873558 |
| 32 | 651383048 |
| 33 | 1310551707 |
| 34 | 2655240565 |
| 35 | 5295397093 |
| 36 | 10338145110 |
| 37 | 21052407259 |
| 38 | 42748787713 |
| 39 | 86078893923 |
| 40 | 169349494068 |