%I #5 Mar 31 2012 12:35:52

%S 4,16,43,128,416,1287,3996,12594,39539,123964,390822,1231115,3878694,

%T 12237024,38612549,121853840,384703976,1214725443,3835937346,

%U 12115116500,38266545975,120874923256,381838415718,1206261483091,3810809904904

%N Number of nX2 0..3 arrays with each element equal to either the sum mod 4 of its horizontal and vertical neighbors or the sum mod 4 of its diagonal and antidiagonal neighbors

%C Column 2 of A183541

%H R. H. Hardin, <a href="/A183536/b183536.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=5*a(n-1)+3*a(n-2)-20*a(n-3)-88*a(n-4)+56*a(n-5)+531*a(n-6)+530*a(n-7)-1530*a(n-8)-4123*a(n-9)-750*a(n-10)+11451*a(n-11)+16890*a(n-12)-4861*a(n-13)-43240*a(n-14)-44432*a(n-15)+29396*a(n-16)+103950*a(n-17)+51683*a(n-18)-96473*a(n-19)-119394*a(n-20)+100330*a(n-21)+204492*a(n-22)-168766*a(n-23)-472266*a(n-24)-101730*a(n-25)+570963*a(n-26)+696382*a(n-27)-155331*a(n-28)-761225*a(n-29)-41580*a(n-30)+512100*a(n-31)+204792*a(n-32)-428106*a(n-33)-775382*a(n-34)+71500*a(n-35)+787132*a(n-36)+59480*a(n-37)-388992*a(n-38)-61056*a(n-39)+165888*a(n-40)

%e Some solutions for 3X2

%e ..1..3....0..0....0..0....2..0....0..0....3..3....3..2....2..0....0..2....2..3

%e ..2..2....2..0....1..0....2..2....0..3....0..0....1..3....2..2....2..1....3..1

%e ..1..3....0..2....0..1....2..0....3..0....1..1....0..3....0..2....1..2....3..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 05 2011