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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 14 |
| 7 | 30 |
| 8 | 62 |
| 9 | 126 |
| 10 | 253 |
| 11 | 509 |
| 12 | 1021 |
| 13 | 2045 |
| 14 | 4092 |
| 15 | 8188 |
| 16 | 16380 |
| 17 | 32764 |
| 18 | 65531 |
| 19 | 131067 |
| 20 | 262139 |
| 21 | 524283 |
| 22 | 1048570 |
| 23 | 2097146 |
| 24 | 4194298 |
| 25 | 8388602 |
| 26 | 16777209 |
| 27 | 33554425 |
| 28 | 67108857 |
| 29 | 134217721 |
| 30 | 268435448 |
| 31 | 536870904 |
| 32 | 1073741816 |
| 33 | 2147483640 |