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 | 27 |
| 5 | 57 |
| 6 | 81 |
| 7 | 171 |
| 8 | 243 |
| 9 | 513 |
| 10 | 729 |
| 11 | 1083 |
| 12 | 1467 |
| 13 | 1539 |
| 14 | 2187 |
| 15 | 3249 |
| 16 | 4401 |
| 17 | 4617 |
| 18 | 6561 |
| 19 | 9747 |
| 20 | 13131 |
| 21 | 13203 |
| 22 | 13851 |
| 23 | 19683 |
| 24 | 20577 |
| 25 | 27873 |
| 26 | 29241 |
| 27 | 32547 |
| 28 | 39393 |
| 29 | 39609 |
| 30 | 41553 |
| 31 | 59049 |
| 32 | 61731 |
| 33 | 83619 |
| 34 | 87723 |
| 35 | 97641 |
| 36 | 118179 |
| 37 | 118827 |
| 38 | 124659 |
| 39 | 177147 |
| 40 | 185193 |