%I
%S 0,0,1,1,0,1,1,0,1,1,1,1,0,0,0,0,0,0,1,0,0,1,0,1,0,1,0,1,1,1,0,1,1,1,
%T 0,1,1,1,1,0,1,0,0,1,0,1,1,1,0,0,1,1,1,1,0,1,1,1,0,0,1,0,1,1,0,0,1,1,
%U 1,0,1,1,0,0,1,1,1,0,0,1,1,0,0,1,1,1,0,1,0,1,1,1,0,1,0,0,0,1,1,1,1,1,1,1,0
%N Binary string formed from the binary expansion of Pi by exchanging 0's and 1's.
%C Binary complement of A004601.
%C May be converted to a decimal number in several ways, depending on where the binary point is inserted: .0011011011110... = 1Pi/4, 0.011011011110... = 2Pi/2 (see A180434), 00.11011011110... = 4Pi.
%t RealDigits[Pi,2,120][[1]]/.{1>0,0>1} (* _Harvey P. Dale_, Apr 02 2015 *)
%Y Cf. A004601, A180434.
%K base,cons,easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Sep 05 2010
%E Verified and edited by _N. J. A. Sloane_, Sep 28 2010
