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 | 1 |
| 3 | 17 |
| 4 | 37 |
| 5 | 77 |
| 6 | 197 |
| 7 | 513 |
| 8 | 993 |
| 9 | 1837 |
| 10 | 2617 |
| 11 | 2637 |
| 12 | 4097 |
| 13 | 5437 |
| 14 | 65537 |
| 15 | 261633 |
| 16 | 364137 |
| 17 | 437837 |
| 18 | 2097153 |
| 19 | 16777217 |
| 20 | 32761917 |
| 21 | 54644032237 |
| 22 | 68719476737 |
| 23 | 137438953473 |
| 24 | 1099511627777 |