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 | 0 |
| 1 | 1 |
| 2 | -1 |
| 3 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | -3 |
| 7 | 1 |
| 8 | 0 |
| 9 | 4 |
| 10 | -8 |
| 11 | 5 |
| 12 | -1 |
| 13 | 8 |
| 14 | -20 |
| 15 | 18 |
| 16 | -7 |
| 17 | 17 |
| 18 | -48 |
| 19 | 56 |
| 20 | -32 |
| 21 | 41 |
| 22 | -113 |
| 23 | 160 |
| 24 | -120 |
| 25 | 114 |
| 26 | -267 |
| 27 | 433 |
| 28 | -400 |
| 29 | 348 |
| 30 | -648 |
| 31 | 1133 |
| 32 | -1233 |
| 33 | 1096 |
| 34 | -1644 |
| 35 | 2914 |
| 36 | -3599 |
| 37 | 3425 |
| 38 | -4384 |
| 39 | 7472 |
| 40 | -10112 |
| 41 | 10449 |
| 42 | -12193 |
| 43 | 19328 |
| 44 | -27696 |
| 45 | 31010 |
| 46 | -34835 |
| 47 | 50849 |
| 48 | -74720 |
| 49 | 89716 |
| 50 | -100680 |