Kubikktall

a) $S_{n+1}=S_n+(n+1{)}^3$ og $S_n=\frac{1}{4}(n^4+2n^3+n^2)$
b) $S_{50}=1625625$
Løsningsforslag S2 eksamen V2024#Oppgave 2-4

\begin{document}

\begin{tikzpicture}
   % Define the size of each small cube
   \def\cubesize{1}
	% Define how many cubes you want to generate
   \foreach \cube [evaluate=\cube as \smallCube using int(\cube-1)] in {1,...,4}{
    \begin{scope}[shift={(\cube^1.9,0)}]

	    % Draw the front face
	    \foreach \x in {0,...,\smallCube}
	        \foreach \y in {0,...,\smallCube}
	            \draw[thick] (\x*\cubesize, \y*\cubesize, 0) -- ++(\cubesize,0,0) -- ++(0,\cubesize,0) -- ++(-\cubesize,0,0) -- cycle;
	
	    % Draw the horizontal connections on the right face
	    \foreach \y in {0,...,\cube}
	        \foreach \z in {0,...,\smallCube}
	            \draw[thick] (\cube*\cubesize, \y*\cubesize, -\z*\cubesize) -- ++(0, 0, -\cubesize);
	    \foreach \x in {0,...,\smallCube}
	        \draw[thick] (\x*\cubesize,\cube*\cubesize,0) -- ++(0,0,-\cube);
	
		% draw all horizontal lines on top
		\foreach \z in {1,...,\cube}
			\draw[thick] (0,\cube*\cubesize,-\z*\cubesize) -- ++({\cube*\cubesize}, 0, 0);
		
		\foreach \z in {1,...,\cube}
			\draw[thick] (\cube,0,-\z*\cubesize) -- (\cube*\cubesize,\cube*\cubesize,-\z*\cubesize);
       \end{scope}
  }
\end{tikzpicture}
\end{document}