Ruby

def nfib(n) if n < 2 then 1 else nfib(n-2) + nfib(n - 1) + 1 end end nfib(10) def sieve(n) size = 8190 flags = Array.new(size + 1, true) count = 0 for iter in 1...n count = 0 for i in 1...size if (flags[i]) prime = i + 1 k = i + prime while (k <= size) flags[k] = false k = k + prime end count = count + 1 end end end return count end sieve(3000)