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 | 3 |
| 3 | -3 |
| 4 | 1 |
| 5 | 1 |
| 6 | -9 |
| 7 | 30 |
| 8 | -45 |
| 9 | 30 |
| 10 | -9 |
| 11 | 1 |
| 12 | -1 |
| 13 | 18 |
| 14 | -123 |
| 15 | 399 |
| 16 | -651 |
| 17 | 588 |
| 18 | -308 |
| 19 | 93 |
| 20 | -15 |
| 21 | 1 |
| 22 | 1 |
| 23 | -30 |
| 24 | 345 |
| 25 | -1921 |
| 26 | 5598 |
| 27 | -9540 |
| 28 | 10212 |
| 29 | -7137 |
| 30 | 3303 |
| 31 | -1003 |
| 32 | 192 |
| 33 | -21 |
| 34 | 1 |
| 35 | -1 |
| 36 | 45 |
| 37 | -780 |
| 38 | 6609 |
| 39 | -29847 |
| 40 | 80718 |
| 41 | -141482 |
| 42 | 168927 |
| 43 | -141636 |
| 44 | 84766 |
| 45 | -36366 |
| 46 | 11091 |
| 47 | -2346 |
| 48 | 327 |
| 49 | -27 |
| 50 | 1 |