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 | 0 |
| 3 | 2 |
| 4 | -2 |
| 5 | 4 |
| 6 | -4 |
| 7 | 6 |
| 8 | -6 |
| 9 | 8 |
| 10 | 10 |
| 11 | -10 |
| 12 | -12 |
| 13 | 14 |
| 14 | -14 |
| 15 | 16 |
| 16 | 18 |
| 17 | 20 |
| 18 | -20 |
| 19 | -22 |
| 20 | 24 |
| 21 | -24 |
| 22 | -26 |
| 23 | 28 |
| 24 | 30 |
| 25 | -32 |
| 26 | 34 |
| 27 | -34 |
| 28 | 36 |
| 29 | -36 |
| 30 | 38 |
| 31 | -42 |
| 32 | 44 |
| 33 | 46 |
| 34 | -46 |
| 35 | 50 |
| 36 | -50 |
| 37 | -52 |
| 38 | -54 |
| 39 | 56 |
| 40 | 58 |
| 41 | 60 |
| 42 | -60 |
| 43 | 64 |
| 44 | -64 |
| 45 | 66 |
| 46 | -66 |
| 47 | -70 |
| 48 | -74 |
| 49 | 76 |
| 50 | -76 |
| 51 | 78 |
| 52 | 80 |
| 53 | -80 |
| 54 | 84 |
| 55 | 86 |
| 56 | 88 |
| 57 | 90 |
| 58 | -90 |
| 59 | -92 |
| 60 | 94 |
| 61 | -94 |
| 62 | 98 |
| 63 | -102 |
| 64 | 104 |
| 65 | -104 |