close all;clear all;clc
      
T=4             % cycle input periodic signal
w=2*pi/T        % frequency [rad] input periodic signal
t=-T:.0001:T;   % [s] time reference
N=16            % amount Fourier series terms
n=[1:N]';       % index
a0=0
bn=(pi./n).*(-cos(2*n*pi/3)+cos(n*pi/3)+cos(5*n*pi/3)-cos(4*n*pi/3));

A1=(a0/2)+bn.*sin(w*n*t);   % individual terms
A2=sum(A1);                 % Fourier terms sum

figure;
hold on

for k=1:1:numel(n)
    plot(t,A1(k,:))
end

plot(t,A2,'LineWidth',2.5)
grid on