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 | -4 |
| 3 | -6 |
| 4 | 0 |
| 5 | -10 |
| 6 | 12 |
| 7 | -14 |
| 8 | 0 |
| 9 | 0 |
| 10 | 20 |
| 11 | -22 |
| 12 | 0 |
| 13 | -26 |
| 14 | 28 |
| 15 | 30 |
| 16 | 0 |
| 17 | -34 |
| 18 | 0 |
| 19 | -38 |
| 20 | 0 |
| 21 | 42 |
| 22 | 44 |
| 23 | -46 |
| 24 | 0 |
| 25 | 0 |
| 26 | 52 |
| 27 | 0 |
| 28 | 0 |
| 29 | -58 |
| 30 | -60 |
| 31 | -62 |
| 32 | 0 |
| 33 | 66 |
| 34 | 68 |
| 35 | 70 |
| 36 | 0 |
| 37 | -74 |
| 38 | 76 |
| 39 | 78 |
| 40 | 0 |
| 41 | -82 |
| 42 | -84 |
| 43 | -86 |
| 44 | 0 |
| 45 | 0 |
| 46 | 92 |
| 47 | -94 |
| 48 | 0 |
| 49 | 0 |
| 50 | 0 |
| 51 | 102 |
| 52 | 0 |
| 53 | -106 |
| 54 | 0 |
| 55 | 110 |
| 56 | 0 |
| 57 | 114 |
| 58 | 116 |
| 59 | -118 |
| 60 | 0 |
| 61 | -122 |
| 62 | 124 |
| 63 | 0 |
| 64 | 0 |
| 65 | 130 |
| 66 | -132 |
| 67 | -134 |
| 68 | 0 |
| 69 | 138 |
| 70 | -140 |
| 71 | -142 |
| 72 | 0 |
| 73 | -146 |
| 74 | 148 |
| 75 | 0 |
| 76 | 0 |
| 77 | 154 |
| 78 | -156 |
| 79 | -158 |
| 80 | 0 |