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 | 3 |
| 4 | 15 |
| 5 | 79 |
| 6 | 511 |
| 7 | 4095 |
| 8 | 6735 |
| 9 | 65535 |
| 10 | 2097151 |
| 11 | 16777215 |
| 12 | 75955411 |
| 13 | 68719476735 |
| 14 | 137438953471 |