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 | 1 |
| 1 | 0 |
| 2 | 3 |
| 3 | 0 |
| 4 | 3 |
| 5 | 9 |
| 6 | 0 |
| 7 | 0 |
| 8 | 18 |
| 9 | 27 |
| 10 | 0 |
| 11 | 0 |
| 12 | 9 |
| 13 | 81 |
| 14 | 81 |
| 15 | 0 |
| 16 | 0 |
| 17 | 0 |
| 18 | 81 |
| 19 | 324 |
| 20 | 243 |
| 21 | 0 |
| 22 | 0 |
| 23 | 0 |
| 24 | 27 |
| 25 | 486 |
| 26 | 1215 |
| 27 | 729 |
| 28 | 0 |
| 29 | 0 |
| 30 | 0 |
| 31 | 0 |
| 32 | 324 |
| 33 | 2430 |
| 34 | 4374 |
| 35 | 2187 |
| 36 | 0 |
| 37 | 0 |
| 38 | 0 |
| 39 | 0 |
| 40 | 81 |
| 41 | 2430 |
| 42 | 10935 |
| 43 | 15309 |
| 44 | 6561 |
| 45 | 0 |
| 46 | 0 |
| 47 | 0 |
| 48 | 0 |
| 49 | 0 |
| 50 | 1215 |
| 51 | 14580 |
| 52 | 45927 |
| 53 | 52488 |
| 54 | 19683 |
| 55 | 0 |
| 56 | 0 |
| 57 | 0 |
| 58 | 0 |
| 59 | 0 |
| 60 | 243 |
| 61 | 10935 |
| 62 | 76545 |
| 63 | 183708 |
| 64 | 177147 |
| 65 | 59049 |