cp's OEIS Frontend

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.

A209588 Number of n X n 0..3 arrays with every element equal to a diagonal or antidiagonal reflection.

Original entry on oeis.org

4, 256, 28672, 51380224, 161128382464, 8084777718513664, 709908161907247808512, 997369854092025849117147136, 2452157460147152961259796760100864
Offset: 1

Views

Author

R. H. Hardin Mar 10 2012

Keywords

Comments

Column 3 of A209593

Examples

			Some solutions for n=3
..3..0..2....2..0..1....0..2..0....3..3..1....0..3..0....0..2..3....2..3..0
..0..2..1....0..1..3....2..3..2....2..0..3....1..2..3....2..0..2....3..1..3
..2..1..0....3..3..2....1..2..1....3..2..3....3..1..3....0..2..1....3..3..0
		

Formula

a(n) = 4 ^ (2*n-(n modulo 2)) * 28 ^ ((n*n-2*n+(n modulo 2))/4)