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%I #4 Mar 24 2018 11:31:04
%S 1,3,8,25,65,226,755,2539,8794,30539,106401,371492,1298761,4544515,
%T 15909548,55710973,195119181,683443550,2394043807,8386437959,
%U 29378680446,102918338575,360542635085,1263055770396,4424759215289,15500920405007
%N Number of nX4 0..1 arrays with every element equal to 0, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.
%C Column 4 of A301608.
%H R. H. Hardin, <a href="/A301604/b301604.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) +5*a(n-2) -4*a(n-3) -17*a(n-4) -19*a(n-5) -47*a(n-6) -34*a(n-7) +65*a(n-8) +269*a(n-9) +416*a(n-10) +777*a(n-11) +1045*a(n-12) +732*a(n-13) -1014*a(n-14) -3998*a(n-15) -8802*a(n-16) -14094*a(n-17) -17263*a(n-18) -13739*a(n-19) -2767*a(n-20) +17372*a(n-21) +41271*a(n-22) +65007*a(n-23) +75036*a(n-24) +65891*a(n-25) +34175*a(n-26) -15372*a(n-27) -68185*a(n-28) -112197*a(n-29) -136950*a(n-30) -125033*a(n-31) -86021*a(n-32) -20228*a(n-33) +39579*a(n-34) +93185*a(n-35) +118900*a(n-36) +106527*a(n-37) +72753*a(n-38) +33858*a(n-39) +4321*a(n-40) -26115*a(n-41) -36386*a(n-42) -32661*a(n-43) -31397*a(n-44) -25000*a(n-45) -13771*a(n-46) -5459*a(n-47) +1317*a(n-48) +8274*a(n-49) +9464*a(n-50) +5692*a(n-51) +2846*a(n-52) +908*a(n-53) -891*a(n-54) -1253*a(n-55) -776*a(n-56) -301*a(n-57) -55*a(n-58) +58*a(n-59) +71*a(n-60) +29*a(n-61) +9*a(n-62) -3*a(n-64) -3*a(n-65) +a(n-66)
%e Some solutions for n=5
%e ..0..0..1..1. .0..1..1..1. .0..0..1..1. .0..0..1..1. .0..1..1..1
%e ..0..0..1..1. .1..1..0..1. .0..0..1..1. .0..0..1..1. .1..1..0..1
%e ..1..1..1..1. .1..1..1..1. .1..0..0..0. .0..0..1..1. .1..1..1..1
%e ..1..1..0..0. .0..0..0..0. .0..0..1..0. .0..0..1..1. .1..0..1..1
%e ..1..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..1. .1..1..1..1
%Y Cf. A301608.
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 24 2018
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