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 | 11 |
| 1 | 33 |
| 2 | 99 |
| 3 | 2727 |
| 4 | 8181 |
| 5 | 243243 |
| 6 | 729729 |
| 7 | 21872187 |
| 8 | 65616561 |
| 9 | 1968319683 |
| 10 | 5904959049 |
| 11 | 177147177147 |
| 12 | 531441531441 |
| 13 | 15943231594323 |
| 14 | 47829694782969 |
| 15 | 1434890714348907 |
| 16 | 4304672143046721 |
| 17 | 129140163129140163 |
| 18 | 387420489387420489 |