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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | -1 |
| 5 | -2 |
| 6 | -3 |
| 7 | -1 |
| 8 | 7 |
| 9 | 11 |
| 10 | 20 |
| 11 | -19 |
| 12 | -87 |
| 13 | -191 |
| 14 | -197 |
| 15 | 1018 |
| 16 | 2681 |
| 17 | 8191 |
| 18 | -5841 |
| 19 | -81289 |
| 20 | -261080 |
| 21 | -620551 |
| 22 | 3033521 |
| 23 | 14480129 |
| 24 | 69664119 |
| 25 | -2664458 |
| 26 | -1612539083 |
| 27 | -7758440129 |
| 28 | -37029252553 |
| 29 | 181003520899 |
| 30 | 1721180313660 |
| 31 | 12437589708389 |
| 32 | 19206818781913 |