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 | 6 |
| 2 | -1 |
| 3 | 45 |
| 4 | -15 |
| 5 | 1 |
| 6 | 360 |
| 7 | -180 |
| 8 | 24 |
| 9 | -1 |
| 10 | 2970 |
| 11 | -1980 |
| 12 | 396 |
| 13 | -33 |
| 14 | 1 |
| 15 | 24948 |
| 16 | -20790 |
| 17 | 5544 |
| 18 | -693 |
| 19 | 42 |
| 20 | -1 |
| 21 | 212058 |
| 22 | -212058 |
| 23 | 70686 |
| 24 | -11781 |
| 25 | 1071 |
| 26 | -51 |
| 27 | 1 |
| 28 | 1817640 |
| 29 | -2120580 |
| 30 | 848232 |
| 31 | -176715 |
| 32 | 21420 |
| 33 | -1530 |
| 34 | 60 |
| 35 | -1 |
| 36 | 15677145 |
| 37 | -20902860 |
| 38 | 9754668 |
| 39 | -2438667 |
| 40 | 369495 |
| 41 | -35190 |
| 42 | 2070 |
| 43 | -69 |
| 44 | 1 |
| 45 | 135868590 |
| 46 | -203802885 |