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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 12 |
| 4 | 256 |
| 5 | 20480 |
| 6 | 6291456 |
| 7 | 7516192768 |
| 8 | 35184372088832 |
| 9 | 648518346341351424 |
| 10 | 47223664828696452136960 |
| 11 | 13617340432139183023890366464 |
| 12 | 15576890575604482885591488987660288 |
| 13 | 70778732319555200400381918345807787982848 |