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 | -2 |
| 2 | 2 |
| 3 | 2 |
| 4 | -6 |
| 5 | -14 |
| 6 | 26 |
| 7 | 178 |
| 8 | 90 |
| 9 | -2382 |
| 10 | -9446 |
| 11 | 13746 |
| 12 | 287194 |
| 13 | 998578 |
| 14 | -3687782 |
| 15 | -56264782 |
| 16 | -208446118 |
| 17 | 1017677490 |
| 18 | 17194912282 |
| 19 | 79540574642 |
| 20 | -317691584294 |
| 21 | -7577787031374 |
| 22 | -47958156443238 |
| 23 | 77252406086578 |
| 24 | 4400217218583642 |
| 25 | 39757699729476274 |
| 26 | 54538870133137690 |