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 | -1 |
| 5 | 7 |
| 6 | 11 |
| 7 | -5 |
| 8 | -33 |
| 9 | -25 |
| 10 | 53 |
| 11 | 123 |
| 12 | 9 |
| 13 | -297 |
| 14 | -363 |
| 15 | 323 |
| 16 | 1273 |
| 17 | 657 |
| 18 | -2415 |
| 19 | -4407 |
| 20 | 957 |
| 21 | 12069 |
| 22 | 11465 |
| 23 | -16887 |
| 24 | -47915 |
| 25 | -12939 |
| 26 | 104431 |
| 27 | 152029 |
| 28 | -85529 |
| 29 | -476579 |
| 30 | -333905 |
| 31 | 803237 |
| 32 | 1752799 |
| 33 | 11597 |
| 34 | -4349949 |
| 35 | -5019855 |
| 36 | 5068735 |
| 37 | 18311655 |
| 38 | 8392559 |
| 39 | -35953969 |