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 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 2 |
| 7 | 4 |
| 8 | 7 |
| 9 | 14 |
| 10 | 28 |
| 11 | 55 |
| 12 | 108 |
| 13 | 212 |
| 14 | 417 |
| 15 | 820 |
| 16 | 1612 |
| 17 | 3169 |
| 18 | 6230 |
| 19 | 12248 |
| 20 | 24079 |
| 21 | 47338 |
| 22 | 93064 |
| 23 | 182959 |
| 24 | 359688 |
| 25 | 707128 |
| 26 | 1390177 |
| 27 | 2733016 |
| 28 | 5372968 |
| 29 | 10562977 |
| 30 | 20766266 |
| 31 | 40825404 |
| 32 | 80260631 |
| 33 | 157788246 |
| 34 | 310203524 |
| 35 | 609844071 |
| 36 | 1198921876 |
| 37 | 2357018348 |
| 38 | 4633776065 |
| 39 | 9109763884 |
| 40 | 17909324244 |
| 41 | 35208804417 |