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 | -4 |
| 3 | 5 |
| 4 | 1 |
| 5 | -12 |
| 6 | 55 |
| 7 | -114 |
| 8 | 94 |
| 9 | 1 |
| 10 | -24 |
| 11 | 238 |
| 12 | -1248 |
| 13 | 3661 |
| 14 | -5736 |
| 15 | 3828 |
| 16 | 1 |
| 17 | -40 |
| 18 | 690 |
| 19 | -6700 |
| 20 | 40053 |
| 21 | -151060 |
| 22 | 351800 |
| 23 | -465000 |
| 24 | 270576 |
| 25 | 1 |
| 26 | -60 |
| 27 | 1595 |
| 28 | -24720 |
| 29 | 247203 |
| 30 | -1665900 |
| 31 | 7660565 |
| 32 | -23745720 |
| 33 | 47560876 |
| 34 | -55805520 |
| 35 | 29400480 |
| 36 | 1 |
| 37 | -84 |
| 38 | 3185 |
| 39 | -72030 |
| 40 | 1081353 |
| 41 | -11344872 |
| 42 | 85234175 |
| 43 | -461800710 |
| 44 | 1790256286 |
| 45 | -4843901664 |
| 46 | 8693117160 |
| 47 | -9320129280 |
| 48 | 4546558080 |