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%I #5 Apr 05 2014 14:21:00
%S 4,21,102,476,2200,10123,46471,213000,975380,4464474,20429739,
%T 93474260,427645941,1956395954,8949898045,40942368765,187294120155,
%U 856787747966,3919414321141,17929510264717,82019155503670,375199231601451
%N Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4
%C Column 2 of A240460
%H R. H. Hardin, <a href="/A240456/b240456.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 8*a(n-1) -20*a(n-2) +34*a(n-3) -84*a(n-4) +92*a(n-5) -68*a(n-6) +222*a(n-7) +13*a(n-8) -251*a(n-9) +25*a(n-10) -495*a(n-11) +485*a(n-12) -44*a(n-13) -180*a(n-14) +554*a(n-15) -648*a(n-16) +14*a(n-17) +152*a(n-18) -190*a(n-19) -140*a(n-20) +397*a(n-21) -273*a(n-22) +75*a(n-23) +167*a(n-24) -136*a(n-25) +27*a(n-26)
%e Some solutions for n=4
%e ..2..0....2..0....0..2....2..2....0..0....2..2....2..2....2..0....0..2....2..2
%e ..0..2....0..0....2..0....2..2....2..2....0..0....2..2....3..2....2..2....3..2
%e ..3..3....0..0....3..2....2..0....3..2....2..2....0..2....2..2....2..0....3..2
%e ..3..1....2..2....3..1....2..2....3..2....0..2....0..3....0..0....2..0....2..2
%K nonn
%O 1,1
%A _R. H. Hardin_, Apr 05 2014
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