Fibonacci Sequence
F(n) = F(n-1) + F(n-2), F(0)=0, F(1)=1
The Fibonacci sequence starts with 0 and 1, and every next number is the sum of the two before it: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144... This deceptively simple pattern appears everywhere in nature, art, architecture, finance, and computer science. The ratio of consecutive Fibonacci numbers converges to the Golden Ratio (phi = 1.618...), one of the most beautiful constants in mathematics.