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 | 0 |
| 3 | 1 |
| 4 | -2 |
| 5 | 1 |
| 6 | -2 |
| 7 | 1 |
| 8 | -4 |
| 9 | 7 |
| 10 | -5 |
| 11 | 7 |
| 12 | -7 |
| 13 | 16 |
| 14 | -13 |
| 15 | 16 |
| 16 | -33 |
| 17 | 38 |
| 18 | -39 |
| 19 | 31 |
| 20 | -75 |
| 21 | 79 |
| 22 | -92 |
| 23 | 118 |
| 24 | -139 |
| 25 | 201 |
| 26 | -230 |
| 27 | 269 |
| 28 | -264 |
| 29 | 494 |
| 30 | -476 |
| 31 | 523 |
| 32 | -780 |
| 33 | 886 |
| 34 | -1095 |
| 35 | 1261 |
| 36 | -1533 |
| 37 | 1857 |
| 38 | -2593 |
| 39 | 2197 |
| 40 | -3367 |
| 41 | 4256 |
| 42 | -4240 |
| 43 | 5816 |
| 44 | -6484 |
| 45 | 7985 |
| 46 | -9800 |
| 47 | 11051 |
| 48 | -12561 |
| 49 | 17530 |
| 50 | -17516 |