This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A339802 #27 Dec 22 2024 15:27:30
%S A339802 6,9,1,2,1,5,8,2,0,9,2,8,7,5,5,4,0,3,3,6,5,8,4,8,1,5,3,6,9,1,2,5,4,4,
%T A339802 9,1,2,8,2,7,8,2,9,7,9,5,4,8,1,3,2,5,0,3,3,7,0,1,4,2,6,9,3,3,1,2,7,4,
%U A339802 6,9,9,2,7,8,1,4,0,0,3,6,9,3,5,5,0,0,5,0,9,4,8,2,5,9,7,8,6,1,5,2,7,4,4,8,3
%N A339802 Decimal expansion of the imaginary part of harmonic number H(1/2 + i*sqrt(3)/2) where i=sqrt(-1).
%C A339802 For real part of H(1/2 + i*sqrt(3)/2) see A339801.
%F A339802 Equals (Pi/2)*tanh(Pi*sqrt(3)/2) - sqrt(3)/2.
%F A339802 Equals Im(Psi(3/2 + i*sqrt(3)/2)).
%F A339802 Equals -sqrt(3)/2 + Im(Psi(1/2 + i*sqrt(3)/2)).
%F A339802 Equals Im((1 + i*sqrt(3))*Sum_{k>=0} 1/((1 + k)*(3 + i*sqrt(3) + 2*k))).
%e A339802 0.691215820928755403365848...
%t A339802 RealDigits[N[Im[HarmonicNumber[1/2 + I Sqrt[3]/2]], 105]][[1]]
%Y A339802 Cf. A256919, A338815, A339135, A339529, A339530, A339605, A339605, A339606, A339801.
%K A339802 nonn,cons
%O A339802 0,1
%A A339802 _Artur Jasinski_, Dec 17 2020