Problem 57815. List numbers such that every sum of consecutive positive integers ending in those numbers is composite

The sequence in question in this problem involves numbers m such that all sums of consecutive positive integers ending with m are composite. The number 12 is not in the sequence because 11+12 is prime. The number 13 is not in the sequence because 13 is prime. However, 14 is in the sequence because all of the sums 14, 14+13, 14+13+12, etc. through 14+13+12+…+1 are composite.
Write a function that returns the nth number in this sequence.
Solve

Solution Stats

72.73% Correct | 27.27% Incorrect
Last Solution submitted on Dec 11, 2025

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers7

Suggested Problems

More from this Author319

Problem Tags

primes sequence triangular

Community Treasure Hunt

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

Start Hunting!