A097576 - OEIS

%I #6 Oct 25 2014 14:06:42

%S 0,1,1,1,1,1,1,2,2,2,2,4,3,3,3,6,3,3,3,6,4,4,4,8,5,5,5,10,5,5,5,10,6,

%T 6,6,12,6,6,6,12,6,6,6,12,8,8,8,16,8,8,8,16,8,8,8,16,10,10,10,20,9,9,

%U 9,18,10,10,10,20,11,11,11,22,11,11,11,22,12,12,12,24,12,12,12,24,12,12,12

%N A 2 X 2 matrix version of A005185: Hofstadter's sequence.

%F A[n_]:=A[n]=A[n-A[n-1][[1, 1]]]+A[n-A[n-2][[1, 2]]]; A[0]:={{0, 1}, {1, 1}}; A[1]:={{1, 1}, {1, 2}};

%t Clear[A, M] (* Hofstadter 2 X 2 Matrix sequence*) (* by Roger L. Bagula *) digits=100 A[n_]:=A[n]=A[n-A[n-1][[1, 1]]]+A[n-A[n-2][[1, 2]]]; A[0]:={{0, 1}, {1, 1}}; A[1]:={{1, 1}, {1, 2}}; (* flattened sequence of 2 X 2 matrices made with a Hofstadter recurrence*) b=Flatten[Table[A[n], {n, 0, digits}]] ListPlot[b, PlotJoined->True]

%Y Cf. A005185.

%K nonn

%O 0,8

%A _Roger L. Bagula_, Aug 28 2004