Added a test to validate implementation against documented known values and removed static from test methods.

Author: n.bitounis

UnitTest/AlgorithmsTests/CatalanNumbersTest.cs

@@ -8,7 +8,7 @@ namespace UnitTest.AlgorithmsTests
     public class CatalanNumbersTest
     {
         [Fact]
-        public static void DoTest()
+        public void DoTest()
         {
             var list = CatalanNumbers.GetRange(0, 100);
             var list2 = new List<BigInteger>();
@@ -22,5 +22,48 @@ public static void DoTest()
                 Assert.True(list[(int)i] == list2[(int)i], "Wrong calculation.");
             }
         }
+
+        // Values retrieved from https://oeis.org/A000108/list.
+        [Theory]
+        [InlineData(0, "1")]
+        [InlineData(1, "1")]
+        [InlineData(2, "2")]
+        [InlineData(3, "5")]
+        [InlineData(4, "14")]
+        [InlineData(5, "42")]
+        [InlineData(6, "132")]
+        [InlineData(7, "429")]
+        [InlineData(8, "1430")]
+        [InlineData(9, "4862")]
+        [InlineData(10, "16796")]
+        [InlineData(11, "58786")]
+        [InlineData(12, "208012")]
+        [InlineData(13, "742900")]
+        [InlineData(14, "2674440")]
+        [InlineData(15, "9694845")]
+        [InlineData(16, "35357670")]
+        [InlineData(17, "129644790")]
+        [InlineData(18, "477638700")]
+        [InlineData(19, "1767263190")]
+        [InlineData(20, "6564120420")]
+        [InlineData(21, "24466267020")]
+        [InlineData(22, "91482563640")]
+        [InlineData(23, "343059613650")]
+        [InlineData(24, "1289904147324")]
+        [InlineData(25, "4861946401452")]
+        [InlineData(26, "18367353072152")]
+        [InlineData(27, "69533550916004")]
+        [InlineData(28, "263747951750360")]
+        [InlineData(29, "1002242216651368")]
+        [InlineData(30, "3814986502092304")]
+        public void ManuallyVerifyCatalanNumber(uint rank, string value)
+        {
+            // This conversion seems to be necessary because as of this
+            // writing xunit doesn't behave well with BigInteger inline
+            // data values.
+            var bigint = BigInteger.Parse(value);
+
+            Assert.True(CatalanNumbers.GetNumber(rank) == bigint);
+        }
     }
 }