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 | 0 |
| 2 | -1 |
| 3 | -1 |
| 4 | 1 |
| 5 | 4 |
| 6 | 4 |
| 7 | -3 |
| 8 | -14 |
| 9 | -15 |
| 10 | 9 |
| 11 | 49 |
| 12 | 56 |
| 13 | -26 |
| 14 | -171 |
| 15 | -208 |
| 16 | 71 |
| 17 | 595 |
| 18 | 769 |
| 19 | -176 |
| 20 | -2064 |
| 21 | -2831 |
| 22 | 354 |
| 23 | 7137 |
| 24 | 10381 |
| 25 | -295 |
| 26 | -24596 |
| 27 | -37926 |
| 28 | -2359 |
| 29 | 84464 |
| 30 | 138079 |
| 31 | 20407 |
| 32 | -288959 |
| 33 | -501060 |
| 34 | -114836 |
| 35 | 984549 |
| 36 | 1812546 |
| 37 | 556609 |
| 38 | -3339871 |
| 39 | -6537023 |
| 40 | -2497824 |
| 41 | 11275550 |