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Number of (4+1)X(n+1) 0..1 arrays with each row divisible by 3 and column not divisible by 3, read as a binary number with top and left being the most significant bits.
1

%I #4 Sep 22 2015 09:36:11

%S 21,48,1701,18228,428301,7577424,163388421,3287265300,69481709901,

%T 1443547193328,30363542104581,635919555126708,13359727300650381,

%U 280364385485387664,5888252348126720901,123632237885054793300

%N Number of (4+1)X(n+1) 0..1 arrays with each row divisible by 3 and column not divisible by 3, read as a binary number with top and left being the most significant bits.

%C Row 4 of A262420.

%H R. H. Hardin, <a href="/A262423/b262423.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 21*a(n-1) +189*a(n-2) -3969*a(n-3) -10719*a(n-4) +225099*a(n-5) +250803*a(n-6) -5266863*a(n-7) -2527200*a(n-8) +53071200*a(n-9) +9062928*a(n-10) -190321488*a(n-11)

%e Some solutions for n=4

%e ..0..0..1..1..0....1..0..1..0..1....1..1..0..0..0....1..0..0..1..0

%e ..0..0..0..0..0....0..1..0..0..1....0..0..0..1..1....1..0..0..1..0

%e ..1..1..0..0..0....1..1..0..1..1....0..0..1..1..0....1..0..0..1..0

%e ..0..1..0..0..1....1..1..0..0..0....0..0..1..1..0....0..1..0..0..1

%e ..0..1..1..0..0....1..0..0..1..0....0..1..1..0..0....0..0..1..1..0

%Y Cf. A262420.

%K nonn

%O 1,1

%A _R. H. Hardin_, Sep 22 2015