How to implement Linked list Concept

how to write this code in the form of Linked list with pointer concept

class Sequence
    {
        public ArrayList Nodes;
        public Sequence Next;
    }
    class Program
    {
        static void Main(string[] args)
        {
            Sequence First, Current, Prev;
            int[] a = { 1, 3, 4, 5, 8, 11, 13, 14, 15, 18, 20, 21,22,23,24 };
            int diff = 1;
            First = Current = Prev = null;
            for (int i = 0; i < a.Length; i++)
            {
                Current = new Sequence();
                if (First == null)
                {
                    First = Current;
                }
                if (Prev != null)
                    Prev.Next = Current;
                Prev = Current;
                Current.Next = null;
                Current.Nodes = new ArrayList();
                for (int j = i+1 ; j < a.Length;j++ )
                {
                    Current.Nodes.Add(a[j-1]);
                    if (a[j] - a[i] == diff)
                        diff++;
                    else
                    {
                        diff = 1;
                        i = j-1;
                        Current = null;
                        break;
                    }
                    if (j == a.Length - 1)
                    {
                        Current.Nodes.Add(a[j]);
                        i = j - 1;                        
                    }
                }
            }
        }
    }

Guna..............