A071004 - OEIS

%I #22 Oct 15 2018 00:03:01

%S 1,0,0,1,1,0,0,1,0,1,0,1,1,1,0,0,1,0,1,0,1,0,0,0,1,1,0,0,0,0,1,0,0,0,

%T 0,1,1,0,1,1,0,0,0,0,0,1,1,0,0,1,0,1,1,1,0,1,0,1,1,0,0,0,1,1,0,0,1,1,

%U 1,1,1,0,1,0,0,0,1,0,1,1,1,0,0,1,1,0,1,1,1,1,0,1,1,0,0,0,0,1,1,0,0,0,0,0,0

%N Binary expansion of AGM(1,sqrt(2)) where AGM(x,y) denote the arithmetic-geometric mean of (x,y).

%H G. C. Greubel, <a href="/A071004/b071004.txt">Table of n, a(n) for n = 1..10000</a>

%t RealDigits[ArithmeticGeometricMean[1,Sqrt[2]],2,120][[1]] (* _Harvey P. Dale_, Mar 30 2015 *)

%o (PARI) a(n)=agm(sqrt(2),1)*2^(n-1)\1%2 \\ _Charles R Greathouse IV_, Mar 03 2016

%Y Cf. A053004.

%K base,cons,nonn

%O 1,1

%A _Benoit Cloitre_, Aug 17 2002