BitContradiction filtering changes to cut invalid divisors during checks.

PerfectNumbers.Core/ByDivisorKIncrementMode.cs

@@ -0,0 +1,16 @@
+namespace PerfectNumbers.Core;
+#pragma warning disable CA2211 // The fields are settable on purpose for the best performance
+
+public enum ByDivisorKIncrementMode
+{
+    Sequential,
+    Pow2Groups,
+    Predictive,
+    Percentile,
+    Additive,
+    TopDown,
+    BitContradiction,
+    BitTree,
+}
+
+#pragma warning restore CA2211 // Non-constant fields should not be visible