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 | 6 |
| 3 | 2 |
| 4 | -10 |
| 5 | 10 |
| 6 | -17 |
| 7 | 84 |
| 8 | -70 |
| 9 | 28 |
| 10 | 124 |
| 11 | -612 |
| 12 | 504 |
| 13 | -168 |
| 14 | 36 |
| 15 | -2764 |
| 16 | 13640 |
| 17 | -11220 |
| 18 | 3696 |
| 19 | -660 |
| 20 | 88 |
| 21 | 43688 |
| 22 | -215592 |
| 23 | 177320 |
| 24 | -58344 |
| 25 | 10296 |
| 26 | -1144 |
| 27 | 104 |
| 28 | -1859138 |
| 29 | 9174480 |
| 30 | -7545720 |
| 31 | 2482480 |
| 32 | -437580 |
| 33 | 48048 |
| 34 | -3640 |
| 35 | 240 |
| 36 | 51236656 |
| 37 | -252842768 |
| 38 | 207954880 |
| 39 | -68414528 |
| 40 | 12057760 |
| 41 | -1322464 |
| 42 | 99008 |
| 43 | -5440 |