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 | 0 |
| 5 | 1 |
| 6 | -1 |
| 7 | -1 |
| 8 | 0 |
| 9 | 1 |
| 10 | -1 |
| 11 | -1 |
| 12 | 1 |
| 13 | 0 |
| 14 | 0 |
| 15 | 0 |
| 16 | 0 |
| 17 | 0 |
| 18 | 0 |
| 19 | 0 |
| 20 | 0 |
| 21 | 0 |
| 22 | 0 |
| 23 | 0 |
| 24 | 1 |
| 25 | 1 |
| 26 | -1 |
| 27 | -1 |
| 28 | 0 |
| 29 | 4 |
| 30 | -16 |
| 31 | -9 |
| 32 | 25 |
| 33 | 4 |
| 34 | -81 |
| 35 | -81 |
| 36 | 81 |
| 37 | 841 |
| 38 | -5929 |
| 39 | -3969 |
| 40 | 19600 |
| 41 | 69169 |
| 42 | -667489 |
| 43 | -285156 |
| 44 | 80656 |
| 45 | 276676 |
| 46 | -790321 |
| 47 | -60025 |
| 48 | 3136 |
| 49 | 10816 |
| 50 | -40000 |
| 51 | -45369 |
| 52 | 221841 |
| 53 | 86436 |
| 54 | -168100 |
| 55 | -12100 |
| 56 | 13225 |
| 57 | 11881 |
| 58 | -87616 |
| 59 | -71289 |
| 60 | 729 |