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 | -2 |
| 5 | -3 |
| 6 | 1 |
| 7 | -3 |
| 8 | -15 |
| 9 | -18 |
| 10 | 1 |
| 11 | -4 |
| 12 | -44 |
| 13 | -144 |
| 14 | -160 |
| 15 | 1 |
| 16 | -5 |
| 17 | -100 |
| 18 | -625 |
| 19 | -1750 |
| 20 | -1875 |
| 21 | 1 |
| 22 | -6 |
| 23 | -195 |
| 24 | -1980 |
| 25 | -10044 |
| 26 | -25920 |
| 27 | -27216 |
| 28 | 1 |
| 29 | -7 |
| 30 | -343 |
| 31 | -5145 |
| 32 | -40817 |
| 33 | -184877 |
| 34 | -453789 |
| 35 | -470596 |
| 36 | 1 |
| 37 | -8 |
| 38 | -560 |
| 39 | -11648 |
| 40 | -132608 |
| 41 | -917504 |
| 42 | -3866624 |
| 43 | -9175040 |
| 44 | -9437184 |
| 45 | 1 |
| 46 | -9 |
| 47 | -864 |
| 48 | -23814 |
| 49 | -367416 |
| 50 | -3582306 |