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 | -5 |
| 4 | 9 |
| 5 | -7 |
| 6 | -9 |
| 7 | 41 |
| 8 | -71 |
| 9 | 51 |
| 10 | 81 |
| 11 | -335 |
| 12 | 559 |
| 13 | -367 |
| 14 | -719 |
| 15 | 2731 |
| 16 | -4391 |
| 17 | 2601 |
| 18 | 6311 |
| 19 | -22215 |
| 20 | 34409 |
| 21 | -18077 |
| 22 | -54879 |
| 23 | 180321 |
| 24 | -268961 |
| 25 | 122401 |
| 26 | 473441 |
| 27 | -1460645 |
| 28 | 2096809 |
| 29 | -798887 |
| 30 | -4056489 |
| 31 | 11807561 |
| 32 | -16301031 |
| 33 | 4930451 |
| 34 | 34548721 |
| 35 | -95259375 |
| 36 | 126351759 |