Problem 58013. Find a number m such that 2m and the square of m have the same digit sum

Created by ChrisR

Solve Later

The number  has the property that  and  have the same digit sum. It is the seventh number, including zero, in the sequence of numbers with that property. 
Write a function to find the nth term in the sequence, where n can be a vector. 

Solve

Solution Stats

13 Solutions
6 Solvers

Last Solution submitted on Jul 28, 2025

Last 200 Solutions

Problem Comments

2 Comments

2 Comments

Christian Schröder on 23 Apr 2023

> It is the sixth number, including zero, in the sequence of numbers with that property.

Isn't it the seventh?

Also, out of curiosity, why are you disallowing persistent variables?

ChrisR on 23 Apr 2023

Yes, seventh--corrected, thanks. Bitten by the "off by one bug" again.

Banning persistent is to add the challenge of dealing with large numbers in Cody time. A while ago I found a quicker way to find the digit sums of a lot of numbers, and this problem was another place to exploit that method.

Solution Comments

Show comments

Problem Recent Solvers6

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 58013. Find a number m such that 2m and the square of m have the same digit sum

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers6

Suggested Problems

More from this Author320

Problem Tags

Community Treasure Hunt

Problem 58013. Find a number m such that 2m and the square of m have the same digit sum

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers6

Suggested Problems

More from this Author320

Problem Tags

Community Treasure Hunt

Players