int.To()

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

class Entry {
    static int Main(string[] args) {
        Console.WriteLine("Hello");
        foreach( int index in 1.To(7) ) {
            Console.WriteLine( index );
        }
        return 0;
    }
}

static class Extensions {
    public static IEnumerable<int> To(this int from, int to, int step = 1) {
        to++;
        while (!(step > 0 ^ from < to) && from != to) {
            yield return from;
            from += step;
        }
    }
}