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A240456 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.

%I A240456 #7 Jun 02 2025 09:58:22
%S A240456 4,21,102,476,2200,10123,46471,213000,975380,4464474,20429739,
%T A240456 93474260,427645941,1956395954,8949898045,40942368765,187294120155,
%U A240456 856787747966,3919414321141,17929510264717,82019155503670,375199231601451
%N A240456 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.
%C A240456 Column 2 of A240460
%H A240456 R. H. Hardin, <a href="/A240456/b240456.txt">Table of n, a(n) for n = 1..210</a>
%F A240456 Empirical: a(n) = 8*a(n-1) -20*a(n-2) +34*a(n-3) -84*a(n-4) +92*a(n-5) -68*a(n-6) +222*a(n-7) +13*a(n-8) -251*a(n-9) +25*a(n-10) -495*a(n-11) +485*a(n-12) -44*a(n-13) -180*a(n-14) +554*a(n-15) -648*a(n-16) +14*a(n-17) +152*a(n-18) -190*a(n-19) -140*a(n-20) +397*a(n-21) -273*a(n-22) +75*a(n-23) +167*a(n-24) -136*a(n-25) +27*a(n-26)
%e A240456 Some solutions for n=4
%e A240456 ..2..0....2..0....0..2....2..2....0..0....2..2....2..2....2..0....0..2....2..2
%e A240456 ..0..2....0..0....2..0....2..2....2..2....0..0....2..2....3..2....2..2....3..2
%e A240456 ..3..3....0..0....3..2....2..0....3..2....2..2....0..2....2..2....2..0....3..2
%e A240456 ..3..1....2..2....3..1....2..2....3..2....0..2....0..3....0..0....2..0....2..2
%K A240456 nonn
%O A240456 1,1
%A A240456 _R. H. Hardin_, Apr 05 2014