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A247675 Decimal expansion of the integral over the square [-1,1]x[-1,1] of 1/sqrt(1+x^2+y^2) dx dy.

%I A247675 #9 Sep 08 2022 08:46:09
%S A247675 3,1,7,3,4,3,6,4,8,5,3,0,6,0,7,1,3,4,2,1,9,1,7,5,6,4,6,7,0,4,5,5,3,8,
%T A247675 5,1,9,9,7,6,4,8,1,6,1,9,6,1,9,9,9,5,3,7,1,7,5,7,2,5,9,2,9,9,4,7,6,6,
%U A247675 2,9,8,0,4,1,4,1,6,3,6,5,7,1,8,7,8,1,8,6,1,7,0,2,3,8,9,9,5,7,5,5,5,7,1
%N A247675 Decimal expansion of the integral over the square [-1,1]x[-1,1] of 1/sqrt(1+x^2+y^2) dx dy.
%H A247675 G. C. Greubel, <a href="/A247675/b247675.txt">Table of n, a(n) for n = 1..10000</a>
%H A247675 D. H. Bailey, J. M. Borwein, <a href="https://escholarship.org/uc/item/4281090t">Highly Parallel, High-Precision Numerical Integration</a> p. 9. (2005) Lawrence Berkeley National Laboratory
%F A247675 Equals 4*log(2 + sqrt(3)) - 2*Pi/3.
%e A247675 3.17343648530607134219175646704553851997648161961999537...
%t A247675 RealDigits[4*Log[2 + Sqrt[3]] - 2*Pi/3, 10, 103] // First
%o A247675 (PARI) default(realprecision, 100); 4*log(2 + sqrt(3)) - 2*Pi/3 \\ _G. C. Greubel_, Aug 31 2018
%o A247675 (Magma) SetDefaultRealField(RealField(100)); R:= RealField(); 4*Log(2 + Sqrt(3)) - 2*Pi(R)/3; // _G. C. Greubel_, Aug 31 2018
%Y A247675 Cf. A244921, A247674.
%K A247675 nonn,cons
%O A247675 1,1
%A A247675 _Jean-François Alcover_, Sep 22 2014