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 | 0 |
| 3 | 1 |
| 4 | -3 |
| 5 | 4 |
| 6 | 1 |
| 7 | -9 |
| 8 | 32 |
| 9 | -36 |
| 10 | 1 |
| 11 | -18 |
| 12 | 131 |
| 13 | -426 |
| 14 | 528 |
| 15 | 1 |
| 16 | -30 |
| 17 | 375 |
| 18 | -2370 |
| 19 | 7544 |
| 20 | -9600 |
| 21 | 1 |
| 22 | -45 |
| 23 | 865 |
| 24 | -8955 |
| 25 | 52414 |
| 26 | -163800 |
| 27 | 213120 |
| 28 | 1 |
| 29 | -63 |
| 30 | 1729 |
| 31 | -26565 |
| 32 | 245854 |
| 33 | -1366932 |
| 34 | 4220376 |
| 35 | -5574240 |
| 36 | 1 |
| 37 | -84 |
| 38 | 3122 |
| 39 | -66696 |
| 40 | 893249 |
| 41 | -7664916 |
| 42 | 41096908 |
| 43 | -125747664 |
| 44 | 167973120 |