A209592 - OEIS

%I #10 Oct 03 2025 15:22:08

%S 8,4096,3932160,241591910400,27831388078080000,

%T 205195258022068224000000,2836619246897071128576000000000,

%U 2509659166022727122011815936000000000000

%N Number of n X n 0..7 arrays with every element equal to a diagonal or antidiagonal reflection.

%C Column 7 of A209593

%H R. H. Hardin, <a href="/A209592/b209592.txt">Table of n, a(n) for n = 1..30</a>

%F a(n) = 8 ^ (2*n-(n modulo 2)) * 120 ^ ((n*n-2*n+(n modulo 2))/4)

%e Some solutions for n=3

%e ..0..3..3....0..2..7....0..3..7....0..4..0....0..7..7....0..7..5....0..4..0

%e ..3..2..7....2..5..5....3..5..3....6..7..4....7..1..2....4..6..7....1..0..4

%e ..4..7..0....7..5..0....3..3..0....6..6..0....7..2..0....5..4..0....1..1..0

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 10 2012