cp's OEIS Frontend

A323864 Number of aperiodic binary arrays of size n.

%I A323864 #13 Aug 23 2019 11:23:33
%S A323864 1,2,4,12,32,60,216,252,912,1494,3960,4092,23904,16380,65016,130920,
%T A323864 324960,262140,1569132,1048572,6281280,8388072,16769016,16777212,
%U A323864 134150880,100663050,268402680,536865840,1610449344,1073741820,8589664080,4294967292,25768888320
%N A323864 Number of aperiodic binary arrays of size n.
%C A323864 An n X k matrix is aperiodic if all n * k rotations of its sequence of rows and its sequence of columns are distinct.
%H A323864 Andrew Howroyd, <a href="/A323864/b323864.txt">Table of n, a(n) for n = 0..200</a>
%F A323864 a(n) = Sum_{d|n} A323860(d, n/d). - _Andrew Howroyd_, Aug 21 2019
%e A323864 The a(4) = 32 arrays:
%e A323864   [0001][0010][0011][0100][0110][0111][1000][1001][1011][1100][1101][1110]
%e A323864 .
%e A323864   [00] [00] [01] [01] [10] [10] [11] [11]
%e A323864   [01] [10] [00] [11] [00] [11] [01] [10]
%e A323864 .
%e A323864   [0] [0] [0] [0] [0] [0] [1] [1] [1] [1] [1] [1]
%e A323864   [0] [0] [0] [1] [1] [1] [0] [0] [0] [1] [1] [1]
%e A323864   [0] [1] [1] [0] [1] [1] [0] [0] [1] [0] [0] [1]
%e A323864   [1] [0] [1] [0] [0] [1] [0] [1] [1] [0] [1] [0]
%t A323864 apermatQ[m_]:=UnsameQ@@Join@@Table[RotateLeft[m,{i,j}],{i,Length[m]},{j,Length[First[m]]}];
%t A323864 zaz[n_]:=Join@@(Table[Partition[#,d],{d,Divisors[n]}]&/@Tuples[{0,1},n]);
%t A323864 Table[Length[Select[zaz[n],apermatQ]],{n,10}]
%Y A323864 Cf. A000740, A027375, A265627, A323351.
%Y A323864 Cf. A323860, A323862, A323863, A323865, A323867, A323869.
%K A323864 nonn
%O A323864 0,2
%A A323864 _Gus Wiseman_, Feb 04 2019
%E A323864 Terms a(18) and beyond from _Andrew Howroyd_, Aug 21 2019