In 1974 LEGO estimated that six 2×4 studded LEGO bricks could be combined together in nearly 103 million ways. However, by using a computer program, math professor Soren Eilers discovered that there were in fact 915,104,765 combinations. LEGO’s initial estimates were so far off because they only took into account bricks stacked upward, one on top of the other. (http://bit.ly/2JhSKw1)