using System;

using System.Collections.Generic;

using System.Linq;

​

string ArrayDisplay(string s) => string.Format("[{0}]", s);

​

string CommaJoin<T>(IEnumerable<T> arr) => string.Join(",", arr);

​

void PrintArrays(int[][] arr) => 

    Console.WriteLine(ArrayDisplay(CommaJoin(arr.Select(inner => ArrayDisplay(CommaJoin(inner))))));

int[][] GenerateArrays(int n) =>

    Enumerable.Range(1, n).Select(x => Enumerable.Range(1, x).ToArray()).ToArray();

​

PrintArrays(GenerateArrays(4));

PrintArrays(GenerateArrays(1));