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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 13 |
| 5 | 27 |
| 6 | 39 |
| 7 | 81 |
| 8 | 117 |
| 9 | 169 |
| 10 | 243 |
| 11 | 351 |
| 12 | 507 |
| 13 | 729 |
| 14 | 1053 |
| 15 | 1521 |
| 16 | 2187 |
| 17 | 2197 |
| 18 | 3159 |
| 19 | 4563 |
| 20 | 6561 |
| 21 | 6591 |
| 22 | 9477 |
| 23 | 13689 |
| 24 | 19683 |
| 25 | 19773 |
| 26 | 28431 |
| 27 | 28561 |
| 28 | 41067 |
| 29 | 59049 |
| 30 | 59319 |
| 31 | 85293 |
| 32 | 85683 |
| 33 | 123201 |
| 34 | 177147 |
| 35 | 177957 |
| 36 | 255879 |
| 37 | 257049 |
| 38 | 369603 |
| 39 | 371293 |
| 40 | 531441 |