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%I #4 Dec 01 2014 18:42:13
%S 220,1982,17216,157312,1405454,12770802,114913804,1040818716,
%T 9388632290,84916233072,766719557970,6930512776886,62601134362556,
%U 565720424690948,5110812449111474,46181028008719378,417235865422683956
%N Number of (n+1)X(4+1) 0..1 arrays with every 2X2 subblock having one or two 1s
%C Column 4 of A251326
%H R. H. Hardin, <a href="/A251322/b251322.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 6*a(n-1) +67*a(n-2) -299*a(n-3) -1066*a(n-4) +4715*a(n-5) +3684*a(n-6) -22554*a(n-7) -2351*a(n-8) +42798*a(n-9) -2598*a(n-10) -36276*a(n-11) +3532*a(n-12) +14102*a(n-13) -1392*a(n-14) -2361*a(n-15) +222*a(n-16) +145*a(n-17) -11*a(n-18) -2*a(n-19)
%e Some solutions for n=4
%e ..0..0..0..1..0....0..1..1..0..1....1..0..0..0..0....0..0..1..0..1
%e ..0..1..0..0..1....0..0..0..0..0....0..0..1..0..1....1..0..1..0..1
%e ..1..0..1..0..0....0..1..0..1..0....1..0..0..1..0....0..0..0..0..0
%e ..1..0..0..1..1....1..0..1..0..0....1..0..1..0..1....1..1..1..0..1
%e ..0..1..1..0..0....1..0..0..0..1....0..1..0..0..1....0..0..0..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 01 2014
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