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 | -2 |
| 3 | -4 |
| 4 | 0 |
| 5 | -6 |
| 6 | 8 |
| 7 | -8 |
| 8 | 0 |
| 9 | 3 |
| 10 | 12 |
| 11 | -12 |
| 12 | 0 |
| 13 | -14 |
| 14 | 16 |
| 15 | 24 |
| 16 | 0 |
| 17 | -18 |
| 18 | -6 |
| 19 | -20 |
| 20 | 0 |
| 21 | 32 |
| 22 | 24 |
| 23 | -24 |
| 24 | 0 |
| 25 | 5 |
| 26 | 28 |
| 27 | 0 |
| 28 | 0 |
| 29 | -30 |
| 30 | -48 |
| 31 | -32 |
| 32 | 0 |
| 33 | 48 |
| 34 | 36 |
| 35 | 48 |
| 36 | 0 |
| 37 | -38 |
| 38 | 40 |
| 39 | 56 |
| 40 | 0 |
| 41 | -42 |
| 42 | -64 |
| 43 | -44 |
| 44 | 0 |
| 45 | -18 |
| 46 | 48 |
| 47 | -48 |
| 48 | 0 |
| 49 | 7 |
| 50 | -10 |
| 51 | 72 |
| 52 | 0 |
| 53 | -54 |
| 54 | 0 |
| 55 | 72 |
| 56 | 0 |
| 57 | 80 |
| 58 | 60 |
| 59 | -60 |
| 60 | 0 |
| 61 | -62 |
| 62 | 64 |
| 63 | -24 |
| 64 | 0 |
| 65 | 84 |
| 66 | -96 |
| 67 | -68 |
| 68 | 0 |
| 69 | 96 |
| 70 | -96 |