function s = seriesB( n );

m = 1:2:(2*n - 1);

s = 6*sqrt(1/3)*[cumsum( (1./m).*(-1/3).^(0:n-1))];

%[¹ /6] = [sqrt(1/3)] * [1/(3^0 * 1) -ÊÊÊÊÊÊÊÊÊÊÊÊÊ

%ÊÊÊÊÊÊÊ 1/(3^1 * 3) + 1/(3^2 * 5) -

%Ê1/ (3^3 * 7)Ê +Ê 1/ (3^4 * 9) - ... ]