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%I #7 Apr 26 2021 21:51:01
%S 6,34,132,396,1264,3962,11886,35914,108556,325668,976552,2931922,
%T 8795766,26370674,79104084,237312252,711756448,2135076202,6405228606,
%U 19214238554,57640739420,172922218260,518757049560,1556255741762,4668767225286
%N Number of (n+2) X (2+2) 0..1 arrays with each row divisible by 7 and column not divisible by 7, read as a binary number with top and left being the most significant bits.
%C Column 2 of A262849.
%H R. H. Hardin, <a href="/A262844/b262844.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-1) -4*a(n-2) +20*a(n-3) -68*a(n-4) +68*a(n-5) -162*a(n-6) +444*a(n-7) -444*a(n-8) +644*a(n-9) -1244*a(n-10) +1244*a(n-11) -1277*a(n-12) +1376*a(n-13) -1376*a(n-14) +1032*a(n-15).
%e Some solutions for n=4
%e ..1..1..1..0....1..1..1..0....1..1..1..0....0..0..0..0....0..0..0..0
%e ..0..1..1..1....0..0..0..0....1..1..1..0....0..0..0..0....0..0..0..0
%e ..0..1..1..1....0..1..1..1....0..0..0..0....0..0..0..0....0..0..0..0
%e ..1..1..1..0....1..1..1..0....0..1..1..1....1..1..1..0....1..1..1..0
%e ..0..0..0..0....1..1..1..0....0..0..0..0....0..1..1..1....0..0..0..0
%e ..0..1..1..1....0..0..0..0....0..0..0..0....0..0..0..0....0..1..1..1
%Y Cf. A262849.
%K nonn
%O 1,1
%A _R. H. Hardin_, Oct 03 2015
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