Find missing number in sequence
To find missing number in sequence, Use below given code : var list = new List<int>(new[] { 1, 2, 4, 7, 9 }); var result = Enumerable.Range(1, 10).Except(list); foreach (int i in result) { Console.WriteLine(i.ToString()); } Console.Read(); When you run above given code you will get missing numbers : 3 5 6 8 10