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%I #11 Sep 08 2022 08:45:41
%S 2,8,8,6,0,7,8,3,2,4,5,0,7,6,6,4,3,0,3,0,3,2,5,6,0,4,5,0,4,1,2,0,1,2,
%T 1,5,5,2,1,0,7,9,6,6,7,9,6,9,9,6,1,7,9,9,4,0,2,8,8,3,6,1,7,4,4,2,4,3,
%U 3,8,6,3,3,8,8,8,3,2,3,3,5,4,6,8,4,7,3,5,3,1,6,4,5,8,7,3,3,7,4,7,5,7,3,1,5
%N Decimal expansion of the Euler-Mascheroni constant divided by 2.
%H G. C. Greubel, <a href="/A155739/b155739.txt">Table of n, a(n) for n = 0..10000</a>
%H Ovidiu Furdui, <a href="http://www.jstor.org/stable/10.4169/math.mag.84.2.150">Problem 1870</a>, Mathematics Magazine, Vol. 84, No. 2 (2011), p. 151; <a href="http://www.jstor.org/stable/10.4169/math.mag.85.2.150">A double zeta sum</a>, Solution to Problem 1870 by Joel Schlosberg, ibid., Vol. 85, No. 2 (2012), p. 156.
%F Equals A001620/2 = (1 + A147533)/4.
%F Equals Sum_{k,m>=1} k*(zeta(k+m)-1)/(k+m)^2 (Furdui, 2011). - _Amiram Eldar_, Jun 09 2022
%e 0.288607832450766430303256045041201215521079667969961799402...
%p evalf(gamma/2) ;
%t RealDigits[EulerGamma/2 , 10, 100][[1]] (* _G. C. Greubel_, Aug 31 2018 *)
%o (PARI) default(realprecision, 100); Euler/2 \\ _G. C. Greubel_, Aug 31 2018
%o (Magma) R:= RealField(100); EulerGamma(R)/2; // _G. C. Greubel_, Aug 31 2018
%Y Cf. A001620, A147533.
%K cons,nonn
%O 0,1
%A _R. J. Mathar_, Jan 26 2009