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 | 2 |
| 2 | -1 |
| 3 | -1 |
| 4 | 2 |
| 5 | -3 |
| 6 | 3 |
| 7 | 0 |
| 8 | -4 |
| 9 | 6 |
| 10 | -6 |
| 11 | 6 |
| 12 | -1 |
| 13 | -12 |
| 14 | 24 |
| 15 | -29 |
| 16 | 23 |
| 17 | 9 |
| 18 | -64 |
| 19 | 114 |
| 20 | -132 |
| 21 | 81 |
| 22 | 78 |
| 23 | -333 |
| 24 | 577 |
| 25 | -627 |
| 26 | 279 |
| 27 | 610 |
| 28 | -1896 |
| 29 | 2979 |
| 30 | -2911 |
| 31 | 672 |
| 32 | 4232 |
| 33 | -10754 |
| 34 | 15576 |
| 35 | -13515 |
| 36 | -591 |
| 37 | 28098 |
| 38 | -61548 |
| 39 | 81664 |
| 40 | -60408 |
| 41 | -27030 |
| 42 | 180784 |
| 43 | -351081 |
| 44 | 425892 |
| 45 | -253838 |
| 46 | -281760 |
| 47 | 1140396 |
| 48 | -1995767 |
| 49 | 2195952 |
| 50 | -930876 |