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 | 4 |
| 6 | 1 |
| 7 | 1 |
| 8 | -4 |
| 9 | -36 |
| 10 | 1 |
| 11 | 1 |
| 12 | -2 |
| 13 | 9 |
| 14 | 576 |
| 15 | 1 |
| 16 | 1 |
| 17 | -4 |
| 18 | -9 |
| 19 | 64 |
| 20 | -14400 |
| 21 | 1 |
| 22 | 1 |
| 23 | 2 |
| 24 | -3 |
| 25 | -8 |
| 26 | -225 |
| 27 | 518400 |
| 28 | 1 |
| 29 | 1 |
| 30 | 2 |
| 31 | -6 |
| 32 | -16 |
| 33 | 40 |
| 34 | -2304 |
| 35 | -25401600 |
| 36 | 1 |
| 37 | 1 |
| 38 | 2 |
| 39 | -9 |
| 40 | -4 |
| 41 | -15 |
| 42 | 324 |
| 43 | 11025 |
| 44 | 1625702400 |
| 45 | 1 |
| 46 | 1 |
| 47 | 2 |
| 48 | 3 |
| 49 | -8 |
| 50 | -25 |
| 51 | 144 |
| 52 | 280 |
| 53 | 147456 |
| 54 | -131681894400 |
| 55 | 1 |
| 56 | 1 |
| 57 | 2 |
| 58 | 3 |
| 59 | -12 |
| 60 | -5 |
| 61 | -24 |
| 62 | 105 |
| 63 | -2240 |
| 64 | -893025 |
| 65 | 13168189440000 |