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A239859 Number of 2 X n 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or one 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 A239859 #6 Jan 24 2023 15:35:00
%S A239859 2,3,9,12,29,63,100,215,468,785,1654,3515,6048,12676,26381,46460,
%T A239859 96810,198286,355994,737992,1493159,2724777,5619409,11263131,20836948,
%U A239859 42752798,85081916,159218104,325067366,643478067,1215731399,2470549558,4871466920
%N A239859 Number of 2 X n 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or one 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 A239859 Row 2 of A239858.
%H A239859 R. H. Hardin, <a href="/A239859/b239859.txt">Table of n, a(n) for n = 1..210</a>
%F A239859 Empirical: a(n) = a(n-1) +a(n-2) +7*a(n-3) -8*a(n-4) -7*a(n-5) +9*a(n-7) +10*a(n-8) -24*a(n-9) +5*a(n-10) +29*a(n-11) -18*a(n-12) -10*a(n-13) -10*a(n-14) +16*a(n-15) +12*a(n-16) -12*a(n-17) for n>21.
%e A239859 Some solutions for n=4
%e A239859 ..3..2..3..2....2..3..3..2....2..3..3..3....3..2..2..2....3..2..3..3
%e A239859 ..2..1..1..3....3..1..1..3....3..2..2..2....2..1..0..0....2..3..2..2
%Y A239859 Cf. A239858.
%K A239859 nonn
%O A239859 1,1
%A A239859 _R. H. Hardin_, Mar 28 2014