Data update

Task/Summarize-primes/C-sharp/summarize-primes.cs

@@ -0,0 +1,61 @@
+internal class Program
+{
+    private static void Main(string[] args)
+    {
+        int sequenceCount = 0;
+        List<long> primes = new();
+        long primeCandidate = 1;
+        Console.WriteLine("   N   Prime     Sum");
+
+        while (primeCandidate < 1000)
+        {
+            if (IsPrime(primeCandidate))
+            {
+                sequenceCount++;
+                primes.Add(primeCandidate);
+                long sequenceSum = primes.Sum();
+
+                if (IsPrime(sequenceSum))
+                {
+                    Console.WriteLine($"{sequenceCount,4} {primeCandidate,7} {sequenceSum,7}");
+                }
+            }
+
+            primeCandidate++;
+        }
+    }
+
+    public static bool IsPrime(long number)
+    {
+        if (number < 2)
+        {
+            return false;
+        }
+
+        if (number % 2 == 0)
+        {
+            return number == 2;
+        }
+
+        if (number % 3 == 0)
+        {
+            return number == 3;
+        }
+
+        int delta = 2;
+        long k = 5;
+
+        while (k * k <= number)
+        {
+            if (number % k == 0)
+            {
+                return false;
+            }
+
+            k += delta;
+            delta = 6 - delta;
+        }
+
+        return true;
+    }
+}