A191220 - OEIS

%I #13 Jun 06 2016 22:23:03

%S 6,5,6,1,7,6,3,4,3,5,5,8,6,8,3,5,3,5,9,9,1,7,8,0,0,1,5,7,8,1,5,2,3,0,

%T 3,9,0,8,9,0,4,7,9,0,4,2,8,0,0,6,8,6,5,5,1,3,1,9,2,4,4,8,6,0,3,0,5,5,

%U 2,9,1,4,0,1,5,3,7,5,7,7,9,4,3,5,3,3,0,0,6,9,0,8,9,9,6,9,7,1,5,6,4,8,3,3,9,5,9,8,4,7

%N Decimal expansion of x, where Arithmetic-Geometric Mean of 1 and x = Pi

%t SetPrecision[

%t Nest[((x - (ArithmeticGeometricMean[1, x] - Pi)/

%t         D[ArithmeticGeometricMean[1, x] - Pi, x]) /. x -> #1) &, 6,

%t   5], 50]

%o (PARI) \p 120

%o solve(x=5,10,agm(x,1)-Pi)

%K nonn,cons

%O 1,1

%A _Joshua Taylor_, May 26 2011