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) |
|---|---|
| 1 | 1 |
| 2 | -4 |
| 3 | 1 |
| 4 | 15 |
| 5 | -6 |
| 6 | 1 |
| 7 | -56 |
| 8 | 28 |
| 9 | -8 |
| 10 | 1 |
| 11 | 210 |
| 12 | -120 |
| 13 | 45 |
| 14 | -10 |
| 15 | 1 |
| 16 | -792 |
| 17 | 495 |
| 18 | -220 |
| 19 | 66 |
| 20 | -12 |
| 21 | 1 |
| 22 | 3003 |
| 23 | -2002 |
| 24 | 1001 |
| 25 | -364 |
| 26 | 91 |
| 27 | -14 |
| 28 | 1 |
| 29 | -11440 |
| 30 | 8008 |
| 31 | -4368 |
| 32 | 1820 |
| 33 | -560 |
| 34 | 120 |
| 35 | -16 |
| 36 | 1 |
| 37 | 43758 |
| 38 | -31824 |
| 39 | 18564 |
| 40 | -8568 |
| 41 | 3060 |
| 42 | -816 |
| 43 | 153 |
| 44 | -18 |
| 45 | 1 |
| 46 | -167960 |
| 47 | 125970 |
| 48 | -77520 |