Problem 60306. Add non-triangular numbers

The nth triangular number is the sum of the first n positive integers. The sequence of triangular numbers starts 1, 3, 6, 10, 15, and 21. These numbers are involved in Cody Problems 5, 291, 44289, 44334, 44732, 55680, 55695, 55705, 55710, and 55715, for example.
Write a function to return the sum of the non-triangular numbers between the nth and (n+1)st triangular numbers. For example, if n = 3, then the function should return 7+8+9 = 24. Beware the banned functions.
Solve

Solution Stats

50.0% Correct | 50.0% Incorrect
Last Solution submitted on Jun 25, 2025

Solution Comments

Show comments

Problem Recent Solvers13

Suggested Problems

More from this Author311

Problem Tags

algebra sequence sum

Community Treasure Hunt

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

Start Hunting!