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 | 4 |
| 2 | 11 |
| 3 | 27 |
| 4 | 63 |
| 5 | 143 |
| 6 | 319 |
| 7 | 703 |
| 8 | 1535 |
| 9 | 3327 |
| 10 | 7167 |
| 11 | 15359 |
| 12 | 32767 |
| 13 | 69631 |
| 14 | 147455 |
| 15 | 311295 |
| 16 | 655359 |
| 17 | 1376255 |
| 18 | 2883583 |
| 19 | 6029311 |
| 20 | 12582911 |
| 21 | 26214399 |
| 22 | 54525951 |
| 23 | 113246207 |
| 24 | 234881023 |
| 25 | 486539263 |
| 26 | 1006632959 |
| 27 | 2080374783 |
| 28 | 4294967295 |
| 29 | 8858370047 |
| 30 | 18253611007 |
| 31 | 37580963839 |