%I
%S 11,23,12,11,1,10,9,1,8,7,1,6,5,1,4,3,1,2,1,1,0,1,1,0,1,1,0,1,1,0,1,1,
%T 0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,
%U 1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1,1,0,1
%N a(0) = 11, a(1) = 23; for n > 1, a(n) = a(n1)  a(n2).
%C Since a(18)=a(19)=1, starting from here the sequence is periodic with period 3: 1,1,0,1,1,0,1,1,0,...  _Emeric Deutsch_, Jul 13 2005
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 1).
%F a(n) = 2/3 + 1/3*cos(2*Pi*n/3) + 1/3*3^(1/2)*sin(2*Pi*n/3) for n >= 19.  _Richard Choulet_, Dec 12 2008
%p a[0]:=11: a[1]:=23: for n from 2 to 120 do a[n]:=abs(a[n1]a[n2]) od: seq(a[n],n=0..120); # _Emeric Deutsch_, Jul 13 2005
%t Join[{11, 23, 12, 11, 1, 10, 9, 1, 8, 7, 1, 6, 5, 1, 4, 3, 1, 2},LinearRecurrence[{0, 0, 1},{1, 1, 0},85]] (* _Ray Chandler_, Aug 25 2015 *)
%Y Cf. A141571.
%K nonn,easy
%O 0,1
%A _Edwin F. Sampang_, Jul 09 2005
%E More terms from _Emeric Deutsch_, Jul 13 2005
