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 | 1 |
| 1 | 5 |
| 2 | 11 |
| 3 | 21 |
| 4 | 39 |
| 5 | 73 |
| 6 | 139 |
| 7 | 269 |
| 8 | 527 |
| 9 | 1041 |
| 10 | 2067 |
| 11 | 4117 |
| 12 | 8215 |
| 13 | 16409 |
| 14 | 32795 |
| 15 | 65565 |
| 16 | 131103 |
| 17 | 262177 |
| 18 | 524323 |
| 19 | 1048613 |
| 20 | 2097191 |
| 21 | 4194345 |
| 22 | 8388651 |
| 23 | 16777261 |
| 24 | 33554479 |
| 25 | 67108913 |
| 26 | 134217779 |
| 27 | 268435509 |
| 28 | 536870967 |
| 29 | 1073741881 |
| 30 | 2147483707 |
| 31 | 4294967357 |
| 32 | 8589934655 |
| 33 | 17179869249 |