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 | -27 |
| 3 | 72 |
| 4 | 0 |
| 5 | -216 |
| 6 | 270 |
| 7 | 0 |
| 8 | -459 |
| 9 | 720 |
| 10 | 0 |
| 11 | -1080 |
| 12 | 936 |
| 13 | 0 |
| 14 | -1350 |
| 15 | 2160 |
| 16 | 0 |
| 17 | -2592 |
| 18 | 2214 |
| 19 | 0 |
| 20 | -2808 |
| 21 | 3600 |
| 22 | 0 |
| 23 | -4752 |
| 24 | 4590 |
| 25 | 0 |
| 26 | -4590 |
| 27 | 6552 |
| 28 | 0 |
| 29 | -7560 |
| 30 | 5184 |
| 31 | 0 |
| 32 | -7371 |
| 33 | 10800 |
| 34 | 0 |
| 35 | -10800 |
| 36 | 9360 |
| 37 | 0 |
| 38 | -9774 |
| 39 | 12240 |
| 40 | 0 |
| 41 | -15120 |
| 42 | 13500 |
| 43 | 0 |
| 44 | -14040 |
| 45 | 17712 |
| 46 | 0 |
| 47 | -19872 |
| 48 | 14760 |