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 | 0 |
| 3 | -1 |
| 4 | 0 |
| 5 | 3 |
| 6 | 2 |
| 7 | -9 |
| 8 | -12 |
| 9 | 35 |
| 10 | 78 |
| 11 | -153 |
| 12 | -544 |
| 13 | 723 |
| 14 | 4170 |
| 15 | -3337 |
| 16 | -35028 |
| 17 | 10851 |
| 18 | 320678 |
| 19 | 57255 |
| 20 | -3178152 |
| 21 | -2190253 |
| 22 | 33864546 |
| 23 | 42120183 |
| 24 | -385314460 |
| 25 | -719159517 |
| 26 | 4649508222 |
| 27 | 12033407591 |
| 28 | -59076411312 |
| 29 | -204022615725 |
| 30 | 784134861818 |
| 31 | 3554417974647 |
| 32 | -10768948801764 |