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 | 2 |
| 2 | 5 |
| 3 | 10 |
| 4 | 19 |
| 5 | 36 |
| 6 | 69 |
| 7 | 134 |
| 8 | 263 |
| 9 | 520 |
| 10 | 1033 |
| 11 | 2058 |
| 12 | 4107 |
| 13 | 8204 |
| 14 | 16397 |
| 15 | 32782 |
| 16 | 65551 |
| 17 | 131088 |
| 18 | 262161 |
| 19 | 524306 |
| 20 | 1048595 |
| 21 | 2097172 |
| 22 | 4194325 |
| 23 | 8388630 |
| 24 | 16777239 |
| 25 | 33554456 |
| 26 | 67108889 |
| 27 | 134217754 |
| 28 | 268435483 |
| 29 | 536870940 |
| 30 | 1073741853 |
| 31 | 2147483678 |