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 | 0 |
| 5 | 1 |
| 6 | -3 |
| 7 | 1 |
| 8 | 1 |
| 9 | 1 |
| 10 | -12 |
| 11 | 4 |
| 12 | 5 |
| 13 | 2 |
| 14 | 1 |
| 15 | -60 |
| 16 | 20 |
| 17 | 25 |
| 18 | 11 |
| 19 | 3 |
| 20 | 1 |
| 21 | -360 |
| 22 | 120 |
| 23 | 150 |
| 24 | 66 |
| 25 | 19 |
| 26 | 4 |
| 27 | 1 |
| 28 | -2520 |
| 29 | 840 |
| 30 | 1050 |
| 31 | 462 |
| 32 | 133 |
| 33 | 29 |
| 34 | 5 |
| 35 | 1 |
| 36 | -20160 |
| 37 | 6720 |
| 38 | 8400 |
| 39 | 3696 |
| 40 | 1064 |
| 41 | 232 |
| 42 | 41 |
| 43 | 6 |
| 44 | 1 |
| 45 | -181440 |
| 46 | 60480 |
| 47 | 75600 |
| 48 | 33264 |
| 49 | 9576 |
| 50 | 2088 |
| 51 | 369 |
| 52 | 55 |
| 53 | 7 |
| 54 | 1 |
| 55 | -1814400 |
| 56 | 604800 |
| 57 | 756000 |
| 58 | 332640 |
| 59 | 95760 |
| 60 | 20880 |
| 61 | 3690 |
| 62 | 550 |
| 63 | 71 |
| 64 | 8 |
| 65 | 1 |