Дмитрий Башинский

if (message.Text == "/register")
Register();

var lines = File.ReadAllLines("file.txt", Encoding.UTF8);

            var queue = new ConcurrentQueue<string>(lines);

            Parallel.ForEach(queue, item =>
            {
                if (queue.TryDequeue(out var line))
                {
                    Console.WriteLine(line);
                }
            });

var size = 10;
var k = 'a';
var nums = Enumerable.Range(1, size).Select(s => (char)(k + s * 2)).ToArray();

var size = 10;
var nums = Enumerable.Range(1, size).Select(s => Math.Pow(2, s)).ToArray();