Construct a cube from 13 blocks, 1 block, 1 and 3 blocks.
See also Box-Packing Theorem, Cube Dissection, de Bruijn's Theorem, Klarner's Theorem, Polycube, Slothouber-Graatsma Puzzle
References
Honsberger, R. Mathematical Gems II. Washington, DC: Math. Assoc. Amer., pp. 77-80, 1976.