diff --git a/generate_numbers.py b/generate_numbers.py
index bef48ad..d65488d 100644
--- a/generate_numbers.py
+++ b/generate_numbers.py
@@ -1,12 +1,15 @@
 def natural_numbers(n):
     #Returns the list of natural numbers
     #Code here
-
+    return list(range(1, n))
 
 def nth_fibonacci(n):
     #Returns n-th fibonacci number
     #Code here
+    sqrt_5 = 5 ** 0.5
+    return int((((1+sqrt_5)/2)**n-((1-sqrt_5)/2)**n)/sqrt_5)
 
-def is_prime(n):
+def is_prime(n, i=2):
     #Return true if 'n' is prime, otherwise returns false
-    #Code here
\ No newline at end of file
+    #Code here
+    return n >= 2 and (i >= n or bool(n % i) and is_prime(n, i + 1))