using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            List<int> source = new List<int>() { 1, 2, 2, 3, 4, 5 };
            var query = source.Arrange().Where(x => x[2] != 4 && !string.Join("", x.ToArray()).Contains("35") && !string.Join("", x.ToArray()).Contains("53"));
            foreach (var item in query)
            {
                Console.WriteLine(string.Join(", ", item.ToArray()));
            }
        }
    }

    static class ArrangeHelper
    {
        private static List<List<int>> Arrange(int n)
        {
            var result = Enumerable.Range(0, n).Select(x => new List<int>() { x }).ToList();
            while (result[0].Count < n)
            {
                result = result.SelectMany(x => Enumerable.Range(0, n).Except(x).Select(y => x.Concat(new List<int>() { y }).ToList())).ToList();
            }
            return result;
        }

        public static IEnumerable<List<T>> Arrange<T>(this List<T> source)
        {
            return Arrange(source.Count).Select(x => x.Select(y => source[y]).ToList());
        }
    }
}

------解决方案--------------------
如果求数目
A66 / 2 - 60 - A55(5/6)

------解决方案--------------------
算错了 -A55（4/6)
头疼

------解决方案--------------------
回溯