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A205249 Number of (n+1) X 3 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same. 1

%I #8 Jun 11 2018 08:03:13

%S 40,168,752,3416,15568,71000,323856,1477272,6738640,30738648,

%T 140215952,639602456,2917580368,13308696920,60708323856,276924225432,

%U 1263204479440,5762173946328,26284460772752,119897955971096,546920858309968

%N Number of (n+1) X 3 0..1 arrays with the number of clockwise edge increases in every 2 X 2 subblock the same.

%C Column 2 of A205255.

%H R. H. Hardin, <a href="/A205249/b205249.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) -7*a(n-2) +2*a(n-3).

%F Empirical g.f.: 8*x*(5 - 9*x + 3*x^2) / ((1 - x)*(1 - 5*x + 2*x^2)). - _Colin Barker_, Jun 11 2018

%e Some solutions for n=4:

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

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

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

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

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

%Y Cf. A205255.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 24 2012

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Last modified April 24 20:08 EDT 2024. Contains 371963 sequences. (Running on oeis4.)