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A225829 Number of binary pattern classes in the (5,n)-rectangular grid: two patterns are in the same class if one of them can be obtained by a reflection or 180 degree rotation of the other. 7

%I

%S 1,20,288,8640,263680,8407040,268517376,8590786560,274882625536,

%T 8796137062400,281475261923328,9007201737768960,288230393868451840,

%U 9223372185031147520,295147906296044322816,9444732974878980833280,302231454974575793668096,9671406557490978467348480

%N Number of binary pattern classes in the (5,n)-rectangular grid: two patterns are in the same class if one of them can be obtained by a reflection or 180 degree rotation of the other.

%H Vincenzo Librandi, <a href="/A225829/b225829.txt">Table of n, a(n) for n = 0..600</a>

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (40,-224,-1280,8192).

%F a(n) = 32*a(n-1) + 32*a(n-2) - 1024*a(n-3)- 2^(3n - 3)*3 with n>2, a(0)=1, a(1)=20, a(2)=288.

%F a(n) = 2^(5n/2-1)*(2^(5n/2-1) + 2^(n/2-1) + 1) if n is even,

%F a(n) = 2^((5n-1)/2-1)*(2^((5n-1)/2) + 2^((n-1)/2) + 5) if n is odd.

%F G.f.: (1-20*x-288*x^2+2880*x^3)/((1-8*x)*(1-32*x)*(1-32*x^2)). [_Bruno Berselli_, May 17 2013]

%t LinearRecurrence[{40,-224,-1280,8192}, {1, 20, 288, 8640}, 20] (* _Bruno Berselli_, May 17 2013 *)

%t CoefficientList[Series[(1 - 20 x - 288 x^2 + 2880 x^3) / ((1 - 8 x) (1 - 32 x) (1 - 32 x^2)), {x, 0, 30}], x] (* _Vincenzo Librandi_, Sep 04 2013 *)

%o (MAGMA) I:=[1, 20, 288, 8640]; [n le 4 select I[n] else 40*Self(n-1)-224*Self(n-2)-1280*Self(n-3)+8192*Self(n-4): n in [1..25]]; // _Vincenzo Librandi_, Sep 04 2013

%Y A005418 is the number of binary pattern classes in the (1,n)-rectangular grid.

%Y A225826 to A225834 are the numbers of binary pattern classes in the (m,n)-rectangular grid, 1 < m < 11 .

%Y A225910 is the table of (m,n)-rectangular grids.

%K nonn,easy

%O 0,2

%A _Yosu Yurramendi_, May 16 2013

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Last modified May 28 17:37 EDT 2020. Contains 334684 sequences. (Running on oeis4.)