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 | -1 |
| 5 | 1 |
| 6 | -1 |
| 7 | 1 |
| 8 | -1 |
| 9 | 1 |
| 10 | 1 |
| 11 | 0 |
| 12 | -1 |
| 13 | -1 |
| 14 | 1 |
| 15 | -1 |
| 16 | -1 |
| 17 | 1 |
| 18 | -19 |
| 19 | -1 |
| 20 | 1 |
| 21 | 1 |
| 22 | 0 |
| 23 | 11 |
| 24 | -53 |
| 25 | -19 |
| 26 | -1 |
| 27 | 1 |
| 28 | -1 |
| 29 | 1 |
| 30 | 43 |
| 31 | -3113 |
| 32 | -709 |
| 33 | -713 |
| 34 | -1 |
| 35 | 1 |
| 36 | 1 |
| 37 | 0 |
| 38 | -289 |
| 39 | 349 |
| 40 | -28813 |
| 41 | -63367 |
| 42 | -629 |
| 43 | -1 |
| 44 | 1 |
| 45 | -1 |
| 46 | -1 |
| 47 | -313 |
| 48 | 174947 |
| 49 | -46721 |
| 50 | -34877471 |
| 51 | -351541 |
| 52 | -1493 |
| 53 | -1 |
| 54 | 1 |
| 55 | 1 |
| 56 | 0 |
| 57 | -581 |
| 58 | 704101 |
| 59 | -20744051 |
| 60 | -2449743889 |
| 61 | -176710589 |
| 62 | -18054401 |
| 63 | -36287 |
| 64 | -1 |
| 65 | 1 |