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 | 0 |
| 3 | 0 |
| 4 | 82 |
| 5 | 864 |
| 6 | 18784 |
| 7 | 622868 |
| 8 | 18061054 |
| 9 | 264895640 |
| 10 | 7886117822 |
| 11 | 128411926952 |
| 12 | 3611823644006 |
| 13 | 56348098488396 |
| 14 | 1548284436152798 |
| 15 | 24535910156176100 |
| 16 | 650456890341276338 |
| 17 | 10364916108987670024 |
| 18 | 267426031403733462626 |