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A200663 Number of 0..3 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 4.

%I A200663 #7 Jun 02 2025 07:19:08
%S A200663 4,10,26,69,175,432,1076,2671,6627,16421,40695,100886,250093,619947,
%T A200663 1536810,3809790,9444489,23412999,58041252,143885484,356695266,
%U A200663 884255363,2192088651,5434237397,13471597487,33396394603,82790419927,205239329905
%N A200663 Number of 0..3 arrays x(0..n-1) of n elements with each no smaller than the sum of its three previous neighbors modulo 4.
%C A200663 Column 3 of A200668
%H A200663 R. H. Hardin, <a href="/A200663/b200663.txt">Table of n, a(n) for n = 1..210</a>
%F A200663 Empirical: a(n) = 3*a(n-1) -a(n-3) -6*a(n-4) -2*a(n-5) +4*a(n-6) +10*a(n-7) +8*a(n-8) -4*a(n-9) -37*a(n-10) +12*a(n-11) +5*a(n-12) +27*a(n-13) +6*a(n-14) -10*a(n-15) -25*a(n-16) -a(n-17) +23*a(n-19) -7*a(n-20) -14*a(n-21) -9*a(n-22) +94*a(n-23) -90*a(n-24) -38*a(n-25) +88*a(n-26) -72*a(n-27) +64*a(n-28) +75*a(n-29) -94*a(n-30) -141*a(n-31) +114*a(n-32) +23*a(n-33) +71*a(n-34) -49*a(n-35) -58*a(n-36) -100*a(n-37) +48*a(n-38) +140*a(n-39) -56*a(n-40) +32*a(n-41) -43*a(n-42) +18*a(n-43) +6*a(n-44) -14*a(n-45) -10*a(n-46) -12*a(n-47) +27*a(n-48) -2*a(n-49) -4*a(n-50) +6*a(n-51) -6*a(n-52) -2*a(n-53) +3*a(n-54) +3*a(n-55) -2*a(n-56) -a(n-57) +5*a(n-58) -5*a(n-59) +2*a(n-63) -a(n-64)
%e A200663 Some solutions for n=6
%e A200663 ..0....2....0....1....1....2....3....1....1....1....2....2....0....1....0....2
%e A200663 ..3....3....2....1....1....2....3....3....3....1....2....3....2....3....3....2
%e A200663 ..3....3....2....3....2....0....3....0....0....2....3....3....2....1....3....0
%e A200663 ..2....2....1....2....1....2....2....1....2....3....3....3....1....1....3....3
%e A200663 ..3....0....1....3....3....3....3....1....2....3....0....2....1....1....2....1
%e A200663 ..1....2....3....2....2....3....3....3....2....1....3....1....2....3....1....1
%K A200663 nonn
%O A200663 1,1
%A A200663 _R. H. Hardin_ Nov 20 2011