Data update

Task/Tau-number/C-sharp/tau-number.cs

@@ -0,0 +1,59 @@
+internal class Program
+{
+    private static void Main(string[] args)
+    {
+        long limit = 100;
+        Console.WriteLine($"The first {limit} tau numbers are:");
+        long count = 0;
+
+        for (long n = 1; count < limit; ++n)
+        {
+            if (IsTauNumber(n))
+            {
+                Console.Write($"{n, 6} ");
+                ++count;
+
+                if (count % 10 == 0)
+                {
+                    Console.WriteLine();
+                }
+            }
+        }
+    }
+
+    private static bool IsTauNumber(long n)
+    {
+        return n % DivisorCount(n) == 0;
+    }
+
+    private static long DivisorCount(long n)
+    {
+        long total = 1;
+        // Deal with powers of 2 first
+        for (; (n & 1) == 0; n >>= 1)
+        {
+            ++total;
+        }
+
+        // Odd prime factors up to the square root
+        for (long p = 3; p * p <= n; p += 2)
+        {
+            long count = 1;
+
+            for (; n % p == 0; n /= p)
+            {
+                ++count;
+            }
+
+            total *= count;
+        }
+
+        // If n > 1 then it's prime
+        if (n > 1)
+        {
+            total *= 2;
+        }
+
+        return total;
+    }
+}