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 | 0 |
| 9 | 1 |
| 10 | 2 |
| 11 | 4 |
| 12 | 8 |
| 13 | 16 |
| 14 | 31 |
| 15 | 62 |
| 16 | 124 |
| 17 | 248 |
| 18 | 496 |
| 19 | 991 |
| 20 | 1980 |
| 21 | 3956 |
| 22 | 7904 |
| 23 | 15792 |
| 24 | 31553 |
| 25 | 63044 |
| 26 | 125964 |
| 27 | 251680 |
| 28 | 502864 |
| 29 | 1004737 |
| 30 | 2007494 |
| 31 | 4011032 |
| 32 | 8014160 |
| 33 | 16012528 |
| 34 | 31993503 |
| 35 | 63923962 |
| 36 | 127721960 |
| 37 | 255192240 |
| 38 | 509881616 |
| 39 | 1018758495 |
| 40 | 2035509496 |