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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | -1 |
| 5 | -1 |
| 6 | -1 |
| 7 | -1 |
| 8 | 3 |
| 9 | 8 |
| 10 | 14 |
| 11 | 21 |
| 12 | 7 |
| 13 | -40 |
| 14 | -134 |
| 15 | -291 |
| 16 | -389 |
| 17 | -188 |
| 18 | 710 |
| 19 | 2906 |
| 20 | 6285 |
| 21 | 8931 |
| 22 | 5477 |
| 23 | -15250 |
| 24 | -66359 |
| 25 | -149426 |
| 26 | -224524 |
| 27 | -154288 |
| 28 | 336695 |
| 29 | 1605033 |
| 30 | 3774375 |
| 31 | 5887736 |
| 32 | 4504451 |
| 33 | -7603388 |
| 34 | -40495514 |
| 35 | -98834842 |
| 36 | -159804251 |
| 37 | -134317549 |
| 38 | 173843349 |
| 39 | 1050099387 |