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 | -3 |
| 6 | 1 |
| 7 | -6 |
| 8 | 5 |
| 9 | 1 |
| 10 | -10 |
| 11 | 25 |
| 12 | 1 |
| 13 | -15 |
| 14 | 75 |
| 15 | -61 |
| 16 | 1 |
| 17 | -21 |
| 18 | 175 |
| 19 | -427 |
| 20 | 1 |
| 21 | -28 |
| 22 | 350 |
| 23 | -1708 |
| 24 | 1385 |
| 25 | 1 |
| 26 | -36 |
| 27 | 630 |
| 28 | -5124 |
| 29 | 12465 |
| 30 | 1 |
| 31 | -45 |
| 32 | 1050 |
| 33 | -12810 |
| 34 | 62325 |
| 35 | -50521 |
| 36 | 1 |
| 37 | -55 |
| 38 | 1650 |
| 39 | -28182 |
| 40 | 228525 |
| 41 | -555731 |
| 42 | 1 |
| 43 | -66 |
| 44 | 2475 |
| 45 | -56364 |
| 46 | 685575 |
| 47 | -3334386 |
| 48 | 2702765 |
| 49 | 1 |