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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | -2 |
| 7 | 4 |
| 8 | -3 |
| 9 | 4 |
| 10 | -6 |
| 11 | 14 |
| 12 | -18 |
| 13 | 30 |
| 14 | -32 |
| 15 | 48 |
| 16 | -73 |
| 17 | 128 |
| 18 | -182 |
| 19 | 286 |
| 20 | -394 |
| 21 | 578 |
| 22 | -804 |
| 23 | 1386 |
| 24 | -1936 |
| 25 | 3172 |
| 26 | -4298 |
| 27 | 7102 |
| 28 | -10202 |
| 29 | 16414 |
| 30 | -23798 |
| 31 | 38056 |
| 32 | -54997 |
| 33 | 86658 |
| 34 | -125180 |
| 35 | 203396 |
| 36 | -292650 |
| 37 | 475536 |
| 38 | -685314 |
| 39 | 1100728 |
| 40 | -1619952 |
| 41 | 2601166 |
| 42 | -3808952 |
| 43 | 6114666 |
| 44 | -9045400 |
| 45 | 14352568 |