Последовательность

using System;

internal class Program
{
    static void Main(string[] args)
    {
        int startNumber = 5;
        int numberMagnification = 7;
        int finishNumber = 103;

        for (int i = startNumber; i <= finishNumber; i += numberMagnification)
        {
            Console.WriteLine(i);
        }

        Console.ReadKey();
    }
}