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 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 512 |
| 5 | 1 |
| 6 | 0 |
| 7 | 43046721 |
| 8 | 65536 |
| 9 | 1 |
| 10 | 0 |
| 11 | 1125899906842624 |
| 12 | 847288609443 |
| 13 | 33554432 |
| 14 | 1 |
| 15 | 0 |
| 16 | 14551915228366851806640625 |
| 17 | 4722366482869645213696 |
| 18 | 150094635296999121 |
| 19 | 68719476736 |
| 20 | 1 |
| 21 | 0 |