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A232734 Decimal expansion of Integral {x=0..infinity} 1/2^(2^x) dx. 0

%I

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

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

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

%N Decimal expansion of Integral {x=0..infinity} 1/2^(2^x) dx.

%F -Ei(-log(2))/log(2), where Ei is the exponential integral function.

%F Also equals (2*integral {x=0..1/2} log(log(1/x)) dx - log(log(2)))/(2*log(2)).

%e 0.546306835952482741736098769624101388937635539081659135416783399176163689841...

%t RealDigits[-ExpIntegralEi[-Log[2]]/Log[2], 10, 100] // First

%o (PARI) eint1(log(2))/log(2) \\ _Charles R Greathouse IV_, Dec 02 2013

%Y Cf. A007400, A007404 (sum instead of integral).

%K nonn,cons

%O 0,1

%A _Jean-Fran├žois Alcover_, Nov 29 2013

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Last modified May 28 01:34 EDT 2020. Contains 334671 sequences. (Running on oeis4.)