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 | 1 |
| 3 | 3 |
| 4 | -4 |
| 5 | 1 |
| 6 | -19 |
| 7 | 27 |
| 8 | -9 |
| 9 | 1 |
| 10 | 211 |
| 11 | -304 |
| 12 | 108 |
| 13 | -16 |
| 14 | 1 |
| 15 | -3651 |
| 16 | 5275 |
| 17 | -1900 |
| 18 | 300 |
| 19 | -25 |
| 20 | 1 |
| 21 | 90921 |
| 22 | -131436 |
| 23 | 47475 |
| 24 | -7600 |
| 25 | 675 |
| 26 | -36 |
| 27 | 1 |
| 28 | -3081513 |
| 29 | 4455129 |
| 30 | -1610091 |
| 31 | 258475 |
| 32 | -23275 |
| 33 | 1323 |
| 34 | -49 |
| 35 | 1 |
| 36 | 136407699 |
| 37 | -197216832 |
| 38 | 71282064 |
| 39 | -11449536 |
| 40 | 1033900 |
| 41 | -59584 |
| 42 | 2352 |
| 43 | -64 |
| 44 | 1 |