%I #14 Feb 07 2017 02:48:02
%S 2,0,5,2,4,6,6,8,2,7,2,6,9,2,7,1,2,2,8,1,7,6,3,3,7,7,9,9,1,7,3,3,8,3,
%T 9,9,1,7,0,8,3,7,7,5,2,9,9,6,5,5,8,2,1,9,3,2,3,7,3,2,4,5,7,7,5,3,4,9,
%U 9,4,1,3,2,8,7,5,2,7,0,6,1,4,6,9,8,5,1,9,8,8,3,9,4,1,3,1,7,5,1,0,8,8,1
%N Decimal expansion of M_8, the 8th Madelung constant (negated).
%D Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Sections 1.10 Madelung's constant, p. 77.
%H G. C. Greubel, <a href="/A261805/b261805.txt">Table of n, a(n) for n = 1..5000</a>
%H Eric Weisstein's MathWorld, <a href="http://mathworld.wolfram.com/MadelungConstants.html">Madelung Constants</a>
%F M_8 = (15/(4*Pi^3))*(8*sqrt(2) - 1)*zeta(1/2)*zeta(7/2).
%e -2.052466827269271228176337799173383991708377529965582...
%t M8 = (15/(4*Pi^3))*(8*Sqrt[2] - 1)*Zeta[1/2]*Zeta[7/2]; RealDigits[M8, 10, 103] // First
%o (PARI) th4(x)=1+2*sumalt(n=1, (-1)^n*x^n^2)
%o intnum(x=0, [oo, 1], (th4(exp(-x))^8-1)/sqrt(Pi*x)) \\ _Charles R Greathouse IV_, Jun 06 2016
%Y Cf. A059750, A088537, A085469, A090734, A247040, A261804.
%K nonn,cons,easy
%O 1,1
%A _Jean-François Alcover_, Sep 01 2015