using System; using System.Collections.Generic; using System.Linq; public class Test { public static void Main() { var results = new List(){1,2,3,4,5,5,5,6,5,1}; var dbResults = new List(); foreach (var element in results.Where(element => dbResults.Count == 0 || dbResults.Last() != element)) { dbResults.Add(element); } foreach(var res in dbResults) { Console.WriteLine(res); } } }