%I #16 Aug 17 2015 02:46:49
%S 3,1,4,1,5,9,2,6,5,3,5,9,5,1,8,2,3,8,3,2,8,8,4,2,3,9,5,1,3,3,7,1,9,5,
%T 7,4,6,4,7,4,3,0,2,5,6,3,7,8,1,8,2,2,2,9,2,9,0,4,4,4,3,1,7,2,5,0,9,1,
%U 3,0,3,0,4,8,2,7,0,4,2,4,1,7,6,1,0,1,2,3,7,5,1,5,3,5,6,7,5,8,5,1,1,9
%N Decimal expansion of Sum_{k=-infinity..+infinity} log(2)/(2^(-k/2) + 2^(k/2)).
%C Differs from Pi by 5.3*10^-12.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/AlmostInteger.html">Almost Integer</a>
%e 3.14159265359518238328842...
%t almostPi = Log[2]/2 + 2*Log[2]*NSum[1/(2^(-k/2) + 2^(k/2)), {k, 1, Infinity}, WorkingPrecision -> 110, NSumTerms -> 100]; RealDigits[almostPi, 10, 102] // First (* _Jean-François Alcover_, Feb 07 2013 *)
%K nonn,cons
%O 0,1
%A _Eric W. Weisstein_, Dec 15 2005