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 | -1 |
| 3 | 1 |
| 4 | -1 |
| 5 | 1 |
| 6 | -1 |
| 7 | 1 |
| 8 | -1 |
| 9 | 1 |
| 10 | -1 |
| 11 | 1 |
| 12 | -1 |
| 13 | 1 |
| 14 | -1 |
| 15 | 1 |
| 16 | 15 |
| 17 | -16 |
| 18 | 17 |
| 19 | -18 |
| 20 | 19 |
| 21 | -20 |
| 22 | 21 |
| 23 | -22 |
| 24 | 23 |
| 25 | -24 |
| 26 | 25 |
| 27 | -26 |
| 28 | 27 |
| 29 | -28 |
| 30 | 29 |
| 31 | -30 |
| 32 | 15 |
| 33 | 1 |
| 34 | -18 |
| 35 | 36 |
| 36 | -55 |
| 37 | 75 |
| 38 | -96 |
| 39 | 118 |
| 40 | -141 |
| 41 | 165 |
| 42 | -190 |
| 43 | 216 |
| 44 | -243 |
| 45 | 271 |
| 46 | -300 |
| 47 | 330 |
| 48 | -345 |
| 49 | 344 |
| 50 | -326 |
| 51 | 290 |
| 52 | -235 |
| 53 | 160 |
| 54 | -64 |
| 55 | -54 |
| 56 | 195 |
| 57 | -360 |
| 58 | 550 |
| 59 | -766 |
| 60 | 1009 |
| 61 | -1280 |
| 62 | 1580 |