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 | 5 |
| 2 | 129 |
| 3 | 7485 |
| 4 | 755265 |
| 5 | 116338005 |
| 6 | 25263540225 |
| 7 | 7328358482445 |
| 8 | 2730934406225025 |
| 9 | 1269262202389906725 |
| 10 | 718835160819268317825 |
| 11 | 486853691847850902700125 |
| 12 | 388278919916351519293663425 |