spread2.rb

def prime(n)

	return true if (n == 2)
	return false if (n.even?)

	f = 3
	while (f < n / 2)
		$f << f
		return false if (n % f == 0)
		f += 2
	end
	return true


end

def seq1()

	$f = []

	l = []
	t = 0
	n = 3
	while (l.size < $c)
		if prime(n) then
			l << $f.size
			$f.clear
		end
		n += 2
	end
	return l
	
end


def f(n)
	c = 0
	while (n != 1)
		n = (3 * n + 1) if (n.odd?)
#		n = (3 * n + 1) / 2 while (n.odd?)
		n = n / 2 if (n.even?)
#		n /= 2 while (n.even?)
		c += 1
	end
	return c
end

def stat(l)
        return 0, 0 if (l.empty?)
        t = t2 = 0
        l.each \
        {
            |x|
            t += x
            t2 += x ** 2
        }
        c = l.size
        a = t.to_f / c
        z = t2.to_f / c - a ** 2
        sd = Math.sqrt(z < 0 ? 0 : z)
        raise if (sd.nan?)
        return a, sd
end

def seq2()

	n = 3
	t = 0
	l = []
	l2 = []
	c = 0
	while (l2.size < $c)
		
		l << f(n)
		n += 2
		
		if (l.size == 100) then
			a, sd = stat(l)
			l2 << a
			l.clear
			c += 1
		end
		
	end
	return l2
	
end

$c = 500

l1 = seq1()
l2 = seq2()

[l1, l2].transpose.each \
{
	|z|
	puts(z.join("\t"))
}