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Fibonacci Sequence Generator

Generate Fibonacci numbers and see convergence to the golden ratio.

Golden ratio (φ)

1.6180339887

F(n+1) ÷ F(n) converges to φ as n → ∞

Index (n)F(n)F(n)/F(n-1)
00
11
211.00000000
322.00000000
431.50000000
551.66666667
681.60000000
7131.62500000
8211.61538462
9341.61904762
10551.61764706
11891.61818182
121441.61797753
132331.61805556
143771.61802575

What is the Fibonacci sequence?

The Fibonacci sequence starts with 0 and 1. Each subsequent number is the sum of the two preceding ones: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, … The sequence appears in nature (flower petal counts, spiral patterns in shells, leaf arrangements) and has deep connections to the golden ratio φ ≈ 1.618033988.

Frequently asked questions

What is the golden ratio?

The golden ratio φ = (1 + √5) ÷ 2 ≈ 1.618033… is an irrational number with the property that φ = 1 + 1/φ. It appears in architecture, art, and nature. The ratio of consecutive Fibonacci numbers F(n+1)/F(n) converges to φ as n increases.

Why does the tool use BigInt?

Fibonacci numbers grow exponentially. By the 50th term, the value exceeds JavaScript's safe integer range (2^53). The tool uses JavaScript BigInt to compute exact integer values without floating-point rounding errors.

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