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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 0 |
| 5 | -2 |
| 6 | 0 |
| 7 | 13 |
| 8 | 0 |
| 9 | -145 |
| 10 | 0 |
| 11 | 2328 |
| 12 | 0 |
| 13 | -49784 |
| 14 | 0 |
| 15 | 1358965 |
| 16 | 0 |
| 17 | -46076544 |
| 18 | 0 |
| 19 | 1902202515 |
| 20 | 0 |
| 21 | -94104681660 |
| 22 | 0 |
| 23 | 5503867176832 |
| 24 | 0 |
| 25 | -376096374571125 |
| 26 | 0 |
| 27 | 29714871818774044 |
| 28 | 0 |
| 29 | -2689473418781240320 |
| 30 | 0 |
| 31 | 276562260699626541509 |
| 32 | 0 |
| 33 | -32073434441440654231749 |
| 34 | 0 |