export function listOfIntegers(
    first_value: number, 
    number_of_numbers: number,
    step: number,
    separator: string) {
        const result: number[] = [];
        for (let i: number= 0; i <number_of_numbers; i++) {
            const value: number = first_value + i * step;
            result.push(value);
        }
        return result.join(separator);
    }