Write a MATLAB program in a script file that finds a positive integer n such that the sum of all the integers 1+2+3+cdots+n is a number between 100 and 1000

 Write a MATLAB program in a script file that finds a positive integer n such that the sum of all the integers 1+2+3+cdots+n is a number between 100 and 1000 whose three digits are identical. As output, the program displays the integer n and the corresponding sum.