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 | 3 |
| 2 | 9 |
| 3 | 15 |
| 4 | 27 |
| 5 | 39 |
| 6 | 81 |
| 7 | 111 |
| 8 | 183 |
| 9 | 243 |
| 10 | 255 |
| 11 | 327 |
| 12 | 363 |
| 13 | 471 |
| 14 | 729 |
| 15 | 2187 |
| 16 | 2199 |
| 17 | 3063 |
| 18 | 4359 |
| 19 | 4375 |
| 20 | 5571 |
| 21 | 6561 |
| 22 | 8751 |
| 23 | 15723 |
| 24 | 19683 |
| 25 | 36759 |
| 26 | 46791 |
| 27 | 59049 |
| 28 | 65535 |
| 29 | 140103 |
| 30 | 177147 |
| 31 | 208191 |
| 32 | 441027 |
| 33 | 531441 |
| 34 | 1594323 |
| 35 | 4190263 |
| 36 | 4782969 |
| 37 | 9056583 |
| 38 | 14348907 |
| 39 | 43046721 |