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%I #8 Feb 21 2018 19:19:39
%S 2,4,7,13,26,52,103,205,410,820,1639,3277,6554,13108,26215,52429,
%T 104858,209716,419431,838861,1677722,3355444,6710887,13421773,
%U 26843546,53687092,107374183,214748365,429496730,858993460,1717986919,3435973837
%N Number of (n+2) X (1+2) 0..1 arrays with each row and column divisible by 5, read as a binary number with top and left being the most significant bits.
%C Column 1 of A262274.
%H R. H. Hardin, <a href="/A262267/b262267.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) - 3*a(n-2) + 3*a(n-3) - 2*a(n-4).
%F Conjectures from _Colin Barker_, Feb 21 2018: (Start)
%F G.f.: x*(2 - 2*x + x^2 - 2*x^3) / ((1 - x)*(1 - 2*x)*(1 + x^2)).
%F a(n) = 1/2 + 2^(2+n)/5 - (1/20-i/20)*((1+2*i)*(-i)^n + (2+i)*i^n) where i=sqrt(-1).
%F (End)
%e Some solutions for n=4:
%e ..0..0..0....0..0..0....1..0..1....1..0..1....0..0..0....0..0..0....0..0..0
%e ..1..0..1....0..0..0....0..0..0....1..0..1....0..0..0....0..0..0....1..0..1
%e ..1..0..1....0..0..0....1..0..1....0..0..0....1..0..1....0..0..0....1..0..1
%e ..1..0..1....1..0..1....0..0..0....1..0..1....1..0..1....0..0..0....0..0..0
%e ..1..0..1....0..0..0....0..0..0....1..0..1....1..0..1....0..0..0....0..0..0
%e ..0..0..0....1..0..1....0..0..0....1..0..1....1..0..1....0..0..0....1..0..1
%Y Cf. A262274.
%K nonn
%O 1,1
%A _R. H. Hardin_, Sep 17 2015
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