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 | -27 |
| 2 | 27 |
| 3 | -9 |
| 4 | 1 |
| 5 | 125 |
| 6 | -375 |
| 7 | 450 |
| 8 | -275 |
| 9 | 90 |
| 10 | -15 |
| 11 | 1 |
| 12 | -343 |
| 13 | 2058 |
| 14 | -5145 |
| 15 | 7007 |
| 16 | -5733 |
| 17 | 2940 |
| 18 | -952 |
| 19 | 189 |
| 20 | -21 |
| 21 | 1 |
| 22 | 729 |
| 23 | -7290 |
| 24 | 30861 |
| 25 | -72927 |
| 26 | 107406 |
| 27 | -104652 |
| 28 | 69768 |
| 29 | -32319 |
| 30 | 10395 |
| 31 | -2277 |
| 32 | 324 |
| 33 | -27 |
| 34 | 1 |
| 35 | -1331 |
| 36 | 19965 |
| 37 | -127776 |
| 38 | 461857 |
| 39 | -1058145 |
| 40 | 1641486 |
| 41 | -1797818 |
| 42 | 1427679 |
| 43 | -834900 |
| 44 | 361790 |
| 45 | -115830 |
| 46 | 27027 |
| 47 | -4466 |
| 48 | 495 |
| 49 | -33 |
| 50 | 1 |