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%I #5 Mar 31 2012 12:35:50
%S 1,28,109,380,2450,12075,55471,286079,1429824,6989477,34856362,
%T 173451524,858586095,4263159553,21172762001,105041615196,521348098233,
%U 2587930504660,12843811121650,63746482751185,316398514788731
%N Number of nX9 binary arrays with each 1 adjacent to exactly one 1 vertically and one 1 horizontally
%C Equivalent to all 1s connected only in 2X2 blocks
%C Column 9 of A183342
%H R. H. Hardin, <a href="/A183341/b183341.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n)=a(n-1)+4*a(n-2)+66*a(n-3)+95*a(n-4)+43*a(n-5)-720*a(n-6)-1911*a(n-7)-1442*a(n-8)+3264*a(n-9)+10821*a(n-10)+19141*a(n-11)+2814*a(n-12)-66628*a(n-13)-89804*a(n-14)+31181*a(n-15)+153550*a(n-16)+92838*a(n-17)+40230*a(n-18)-70110*a(n-19)-229684*a(n-20)-107631*a(n-21)-94711*a(n-22)+28881*a(n-23)+390574*a(n-24)+124645*a(n-25)-26599*a(n-26)-25097*a(n-27)-277598*a(n-28)+259486*a(n-29)+159878*a(n-30)-12870*a(n-31)-21470*a(n-32)-444709*a(n-33)-78037*a(n-34)-123573*a(n-35)+71536*a(n-36)+64021*a(n-37)-594*a(n-38)+19314*a(n-39)-12660*a(n-40)+3610*a(n-41)+920*a(n-42)-1448*a(n-43)+704*a(n-44)-128*a(n-45)
%e Some solutions for 5X9
%e ..0..0..0..0..1..1..0..1..1....0..0..0..0..1..1..0..0..0
%e ..0..0..0..0..1..1..0..1..1....1..1..0..0..1..1..0..0..0
%e ..0..0..0..0..0..0..0..0..0....1..1..0..0..0..0..0..1..1
%e ..1..1..0..0..1..1..0..0..0....0..0..0..1..1..0..0..1..1
%e ..1..1..0..0..1..1..0..0..0....0..0..0..1..1..0..0..0..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Jan 04 2011
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