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A240793 Number of 2Xn 0..3 arrays with no element equal to one 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 zero plus the sum of the elements antidiagonally to its northeast, modulo 4.

%I A240793 #6 Jun 02 2025 10:00:09
%S A240793 3,4,5,10,14,24,53,70,140,237,396,730,1242,2166,3743,6547,11397,19760,
%T A240793 34622,59868,104358,181794,315863,550264,957027,1665335,2897587,
%U A240793 5042553,8774919,15266419,26569228,46226952,80439383,139977422,243558497
%N A240793 Number of 2Xn 0..3 arrays with no element equal to one 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 zero plus the sum of the elements antidiagonally to its northeast, modulo 4.
%C A240793 Row 2 of A240792
%H A240793 R. H. Hardin, <a href="/A240793/b240793.txt">Table of n, a(n) for n = 1..210</a>
%F A240793 Empirical: a(n) = 2*a(n-2) +4*a(n-3) -a(n-4) -3*a(n-5) -a(n-6) +a(n-7) -9*a(n-8) -9*a(n-9) +8*a(n-10) +15*a(n-11) +4*a(n-12) -15*a(n-13) +2*a(n-14) +3*a(n-15) +7*a(n-16) -7*a(n-17) for n>21
%e A240793 Some solutions for n=4
%e A240793 ..3..2..3..2....3..2..3..3....3..3..2..3....3..2..3..2....3..2..3..2
%e A240793 ..3..2..1..2....3..2..1..1....2..1..2..3....3..2..3..2....3..2..1..1
%K A240793 nonn
%O A240793 1,1
%A A240793 _R. H. Hardin_, Apr 12 2014