%I #10 Feb 24 2016 11:30:48
%S 1,7,8,1,5,8,0,6,9,0,1,0,1,4,6,1,6,2,3,5,7,8,5,8,3,6,6,1,8,0,0,2,9,8,
%T 2,7,7,8,7,9,8,0,9,9,5,4,4,6,6,6,7,4,0,1,7,9,0,3,0,4,2,3,9,1,4,1,0,6,
%U 0,0,2,9,4,3,9,6,4,9,7,2,9,6,8,7,4,7,6,4,6,9,9,8,9,9,8,6,7,3,7,6,7,1,2,4,8
%N Decimal expansion of the first negative root of the equation Gamma(x) + Psi(x) = 0, negated.
%C Gamma(x) stands for the gamma function (Euler's integral of the second kind), Psi(x) denotes the digamma function (logarithmic derivative of the gamma function).
%e -1.7815806901014616235785836618002982778798099544666740...
%p Digits:= 150: fsolve(GAMMA(x)+Psi(x)=0, x=-1.8);
%t FindRoot[Gamma[x]+PolyGamma[x]==0, {x,-1.8}, WorkingPrecision->120][[1, 2]] // RealDigits[#, 10, 105]& // First
%o (PARI) default(realprecision, 120); solve(x = -1.80,-1.76, gamma(x)+psi(x))
%Y Cf. A268893, A268980, A268981.
%K nonn,cons
%O 1,2
%A _Iaroslav V. Blagouchine_, Feb 16 2016