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Number of nX3 0..3 arrays with no element equal to zero plus the sum of elements to its left or two plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4
1

%I #4 Apr 03 2014 16:03:35

%S 8,26,206,974,8064,38252,316962,1502948,12468758,59122266,490548594,

%T 2326075252,19300603720,91520046552,759392572070,3600913438102,

%U 29878821186710,141680483207634,1175603702913842,5574521174572456

%N Number of nX3 0..3 arrays with no element equal to zero plus the sum of elements to its left or two plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4

%C Column 3 of A240295

%H R. H. Hardin, <a href="/A240291/b240291.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 63*a(n-2) -1109*a(n-4) +7143*a(n-6) -395*a(n-8) -201246*a(n-10) +762860*a(n-12) +347011*a(n-14) -7366154*a(n-16) +11744674*a(n-18) +3758987*a(n-20) +10095295*a(n-22) -126415852*a(n-24) +204390541*a(n-26) -65238786*a(n-28) -59211883*a(n-30) -114625640*a(n-32) +381020006*a(n-34) -342073760*a(n-36) +16725276*a(n-38) +181283664*a(n-40) -110895680*a(n-42) +16492080*a(n-44) +1175136*a(n-46) +390464*a(n-48) for n>50

%e Some solutions for n=4

%e ..3..1..1....1..3..1....3..1..1....3..1..3....1..3..3....3..1..3....3..1..3

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 03 2014