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%I #6 May 28 2014 07:55:04
%S 1,7,6,4,2,9,7,3,3,1,3,0,8,0,2,4,3,0,3,4,4,2,9,4,8,0,4,7,6,1,6,7,0,3,
%T 0,2,3,6,1,7,8,1,4,8,8,2,8,0,0,6,9,6,2,5,2,0,1,0,3,1,9,9,1,3,2,5,8,1,
%U 2,3,5,1,1,5,1,9,5,4,4,7,2,0,6,0,5,4,1,0,3,6,3,6,3,2,9,3,8,1,5,9,6
%N Decimal expansion of H, an auxiliary constant used to evaluate some Ising-related constants on triangular and hexagonal lattices (negated).
%D Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, Section 5.22 Lenz-Ising constants, p. 400.
%H Eric Weisstein's MathWorld, <a href="http://mathworld.wolfram.com/DigammaFunction.html">Digamma Function</a>
%F sqrt(3)/(6*Pi)*psi'(1/6) - Pi/sqrt(3) - log(6), where psi' is the derivative of the digamma function.
%e -0.1764297331308024303442948047616703...
%t Sqrt[3]/(6*Pi)*PolyGamma[1, 1/6] - Pi/Sqrt[3] - Log[6] // RealDigits[#, 10, 101]& // First
%K nonn,cons
%O 0,2
%A _Jean-François Alcover_, May 28 2014