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 | 9 |
| 2 | 21 |
| 3 | 45 |
| 4 | 93 |
| 5 | 189 |
| 6 | 381 |
| 7 | 657 |
| 8 | 765 |
| 9 | 873 |
| 10 | 1317 |
| 11 | 1533 |
| 12 | 1749 |
| 13 | 2457 |
| 14 | 2637 |
| 15 | 3069 |
| 16 | 3501 |
| 17 | 4329 |
| 18 | 4917 |
| 19 | 5241 |
| 20 | 5277 |
| 21 | 5745 |
| 22 | 6141 |
| 23 | 6345 |
| 24 | 7005 |
| 25 | 8661 |
| 26 | 9561 |
| 27 | 9837 |
| 28 | 10017 |
| 29 | 10485 |
| 30 | 10557 |
| 31 | 11493 |
| 32 | 12285 |
| 33 | 12693 |
| 34 | 14013 |
| 35 | 15129 |
| 36 | 17325 |
| 37 | 17985 |
| 38 | 19125 |
| 39 | 19677 |
| 40 | 20037 |
| 41 | 20973 |
| 42 | 21117 |
| 43 | 21969 |
| 44 | 22989 |
| 45 | 24573 |
| 46 | 25389 |
| 47 | 26793 |
| 48 | 28029 |
| 49 | 30261 |
| 50 | 31545 |
| 51 | 34653 |
| 52 | 35973 |