sidef-scripts/Math/fibonacci_closed_solution.sf

#!/usr/bin/ruby

func fibonacci (n) {

    define S = (1.25.sqrt + 0.5)
    define T = (-S + 1)
    define U = (-T + S)

    (S**n - T**n) / U -> round
}

for i in (0..20) {
    say fibonacci(i)
}