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 | 1 |
| 1 | 1 |
| 2 | -1 |
| 3 | 1 |
| 4 | -3 |
| 5 | 1 |
| 6 | 1 |
| 7 | -6 |
| 8 | 7 |
| 9 | -1 |
| 10 | 1 |
| 11 | -10 |
| 12 | 25 |
| 13 | -15 |
| 14 | 1 |
| 15 | 1 |
| 16 | -15 |
| 17 | 65 |
| 18 | -90 |
| 19 | 31 |
| 20 | -1 |
| 21 | 1 |
| 22 | -21 |
| 23 | 140 |
| 24 | -350 |
| 25 | 301 |
| 26 | -63 |
| 27 | 1 |
| 28 | 1 |
| 29 | -28 |
| 30 | 266 |
| 31 | -1050 |
| 32 | 1701 |
| 33 | -966 |
| 34 | 127 |
| 35 | -1 |
| 36 | 1 |
| 37 | -36 |
| 38 | 462 |
| 39 | -2646 |
| 40 | 6951 |
| 41 | -7770 |
| 42 | 3025 |
| 43 | -255 |
| 44 | 1 |
| 45 | 1 |
| 46 | -45 |
| 47 | 750 |
| 48 | -5880 |
| 49 | 22827 |
| 50 | -42525 |
| 51 | 34105 |
| 52 | -9330 |
| 53 | 511 |
| 54 | -1 |