Problem 58 and update gitignore

.gitignore

@@ -58,3 +58,4 @@ docs/_build/
 # PyBuilder
 target/
 
+*.swp

problem-58.py

@@ -0,0 +1,26 @@
+
+from primes import is_prime
+
+diags = [1]
+nums = [1]
+spiral = 1
+primes = []
+
+if __name__ == '__main__':
+    while True:
+        spiral += 2
+        circ = list(range(diags[-1] + 1, spiral**2+1))
+        stride = int(len(circ) / 4)
+        corners = [circ[stride*1-1],
+                   circ[stride*2-1],
+                   circ[stride*3-1],
+                   circ[stride*4-1]
+                   ]
+        diags.extend(corners)
+        primes.extend([num for num in corners if is_prime(num)])
+        if len(primes) / len(diags) < 0.1:
+            break
+    print(len(primes), len(diags), spiral)
+
+
+