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A240371 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4.

%I A240371 #7 Jun 02 2025 09:51:46
%S A240371 3,11,21,67,155,353,998,2256,5639,14624,34169,87040,216484,522354,
%T A240371 1320708,3242252,7968236,19928605,48905783,121065218,300575628,
%U A240371 739878493,1834210821,4538220894,11200994822,27751051195,68588966317,169541251841
%N A240371 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4.
%C A240371 Column 2 of A240376
%H A240371 R. H. Hardin, <a href="/A240371/b240371.txt">Table of n, a(n) for n = 1..210</a>
%F A240371 Empirical: a(n) = 3*a(n-2) +10*a(n-3) -3*a(n-4) -6*a(n-5) -3*a(n-6) +8*a(n-7) -7*a(n-8) -9*a(n-9) -4*a(n-10) +13*a(n-11) -14*a(n-12) +17*a(n-13) -a(n-15) for n>17
%e A240371 Some solutions for n=4
%e A240371 ..3..2....3..3....3..3....3..2....3..3....3..2....3..3....2..2....3..2....3..2
%e A240371 ..2..0....3..2....3..2....3..2....3..1....2..1....3..1....2..1....3..1....3..1
%e A240371 ..3..1....2..0....2..0....2..0....2..2....3..1....2..0....3..1....2..2....2..2
%e A240371 ..3..1....3..1....3..3....3..3....2..1....2..2....2..0....3..2....2..0....2..1
%K A240371 nonn
%O A240371 1,1
%A A240371 _R. H. Hardin_, Apr 04 2014