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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 5 |
| 6 | 6 |
| 7 | 9 |
| 8 | 9 |
| 9 | 12 |
| 10 | 9 |
| 11 | 9 |
| 12 | 0 |
| 13 | -9 |
| 14 | -27 |
| 15 | -54 |
| 16 | -81 |
| 17 | -135 |
| 18 | -162 |
| 19 | -243 |
| 20 | -243 |
| 21 | -324 |
| 22 | -243 |
| 23 | -243 |
| 24 | 0 |
| 25 | 243 |
| 26 | 729 |
| 27 | 1458 |
| 28 | 2187 |
| 29 | 3645 |
| 30 | 4374 |
| 31 | 6561 |
| 32 | 6561 |
| 33 | 8748 |
| 34 | 6561 |
| 35 | 6561 |
| 36 | 0 |
| 37 | -6561 |
| 38 | -19683 |
| 39 | -39366 |
| 40 | -59049 |
| 41 | -98415 |
| 42 | -118098 |
| 43 | -177147 |
| 44 | -177147 |
| 45 | -236196 |
| 46 | -177147 |
| 47 | -177147 |
| 48 | 0 |
| 49 | 177147 |
| 50 | 531441 |
| 51 | 1062882 |
| 52 | 1594323 |