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A241398 Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.

%I A241398 #6 Jun 02 2025 10:07:43
%S A241398 3,5,9,23,44,93,204,368,761,1583,2951,6056,12244,23588,47945,95715,
%T A241398 187731,378531,752679,1489014,2986657,5934705,11787915,23567455,
%U A241398 46847503,93218990,186017656,369978815,736728537,1468604461,2922396725,5820645191
%N A241398 Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.
%C A241398 Row 2 of A241397
%H A241398 R. H. Hardin, <a href="/A241398/b241398.txt">Table of n, a(n) for n = 1..210</a>
%F A241398 Empirical: a(n) = 2*a(n-2) +8*a(n-3) -a(n-4) -10*a(n-5) -18*a(n-6) +8*a(n-7) +20*a(n-8) +20*a(n-9) -24*a(n-10) -22*a(n-11) -a(n-12) +32*a(n-13) +8*a(n-14) -3*a(n-15) -12*a(n-16) +4*a(n-17) -5*a(n-18) -4*a(n-20) -3*a(n-21) +2*a(n-22) for n>23
%e A241398 Some solutions for n=4
%e A241398 ..3..2..2..2....2..3..2..2....3..2..3..2....2..3..3..2....3..2..3..3
%e A241398 ..2..0..1..0....2..1..0..0....2..1..1..2....2..1..1..2....1..2..1..2
%K A241398 nonn
%O A241398 1,1
%A A241398 _R. H. Hardin_, Apr 20 2014