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 | 1 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 2 |
| 10 | 4 |
| 11 | 8 |
| 12 | 16 |
| 13 | 31 |
| 14 | 62 |
| 15 | 124 |
| 16 | 248 |
| 17 | 495 |
| 18 | 988 |
| 19 | 1972 |
| 20 | 3936 |
| 21 | 7856 |
| 22 | 15681 |
| 23 | 31300 |
| 24 | 62476 |
| 25 | 124704 |
| 26 | 248913 |
| 27 | 496838 |
| 28 | 991704 |
| 29 | 1979472 |
| 30 | 3951088 |
| 31 | 7886495 |
| 32 | 15741690 |
| 33 | 31420904 |
| 34 | 62717104 |
| 35 | 125185295 |
| 36 | 249873752 |
| 37 | 498755800 |
| 38 | 995532128 |
| 39 | 1987113168 |