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.

A209589 Number of n X n 0..4 arrays with every element equal to a diagonal or antidiagonal reflection.

Original entry on oeis.org

5, 625, 140625, 791015625, 8009033203125, 2027286529541015625, 923682425022125244140625, 10521320122517645359039306640625, 215719941636994597502052783966064453125
Offset: 1

Views

Author

R. H. Hardin Mar 10 2012

Keywords

Comments

Column 4 of A209593

Examples

			Some solutions for n=3
..0..1..0....2..2..3....2..3..1....1..4..0....2..2..2....0..3..3....1..1..3
..1..2..2....1..2..2....3..2..2....4..2..0....2..1..4....4..0..3....1..3..3
..4..2..2....4..1..3....3..2..4....1..0..1....1..4..2....4..4..0....1..3..1
		

Formula

a(n) = 5 ^ (2*n-(n modulo 2)) * 45 ^ ((n*n-2*n+(n modulo 2))/4)