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 | -3 |
| 2 | 4 |
| 3 | -4 |
| 4 | 2 |
| 5 | 6 |
| 6 | -22 |
| 7 | 46 |
| 8 | -74 |
| 9 | 86 |
| 10 | -40 |
| 11 | -120 |
| 12 | 450 |
| 13 | -958 |
| 14 | 1506 |
| 15 | -1694 |
| 16 | 744 |
| 17 | 2500 |
| 18 | -9184 |
| 19 | 19422 |
| 20 | -30450 |
| 21 | 34032 |
| 22 | -14178 |
| 23 | -52286 |
| 24 | 188038 |
| 25 | -394724 |
| 26 | 615102 |
| 27 | -681110 |
| 28 | 268666 |
| 29 | 1089974 |
| 30 | -3847390 |
| 31 | 8021030 |
| 32 | -12426638 |
| 33 | 13632728 |
| 34 | -5063588 |
| 35 | -22711916 |
| 36 | 78708912 |
| 37 | -162966020 |
| 38 | 251005706 |