Solve problems 129 and 130.

python/e130.py

@@ -0,0 +1,32 @@
+from math import gcd
+from lib_prime import is_prime_rabin_miller
+
+
+def r_modulo_closed_form(n, m):
+    assert n > 0 and m > 0
+    return ((pow(10, n, 9 * m) - 1) // 9) % m
+
+
+def a_special(n):
+    k = n - 1
+    if r_modulo_closed_form(k, n) == 0:
+        return k
+    return None
+
+
+def euler_130():
+    c, r = 0, 0
+    for n in range(2, 10**9):
+        if gcd(n, 10) == 1 and not is_prime_rabin_miller(n):
+            if a_special(n) is not None:
+                r += n
+                c += 1
+            if c == 25:
+                break
+    return r
+
+
+if __name__ == "__main__":
+    solution = euler_130()
+    print("e130.py: " + str(solution))
+    assert(solution == 149253)