%I #4 Dec 04 2014 12:01:06

%S 30377,546525,11314071,216137483,4060878845,77906507591,1498035497513,

%T 28691083120021,549693762159617,10541959853810087,202160251694906929,

%U 3876276632392216321,74329842782534694397,1425379360351558502261

%N Number of ways to place any number of black and any number of white nonattacking knights on a (n+2)X(2+2) board

%C Column 2 of A251531

%H R. H. Hardin, <a href="/A251527/b251527.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=1

%e ..2..0..0..2....0..2..0..0....2..1..0..1....2..1..0..0....1..0..0..0

%e ..2..0..0..1....2..1..0..0....0..1..0..0....0..1..2..0....2..0..1..0

%e ..1..0..0..1....2..0..2..0....0..2..0..1....0..0..1..1....0..1..2..0

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 04 2014