Here’s a quick one. In 1977 the magazine Popular Computing sought “problem situations for which the computer is the best (if not the only) tool for solution” and proposed the Z-sequence as a candidate “problem situation:”
a1 = a2 = 1 and a_n = |2 a_{n-2} + a_{n-1} – n| for n > 2
Among the Z-sequence’s properties, the magazine staff pointed out that “successive values seem unpredictable; that is, the values jump around, but not too wildly” and “almost every integer appears as a term in the sequence sooner or later, except for a few numbers, such as 245, 449, 569, 575, and 903.”
Write a function to find the index of the first occurrence of k (including the five numbers above) in the Popular Computing Z-sequence.
Solve

Solution Stats

29 Solutions

17 Solvers

Last Solution submitted on May 25, 2026

Last 200 Solutions

Problem Comments

Solution Comments

Show comments

Problem Recent Solvers17

Chris Cleveland George Berken DH Lorenzo

Suggested Problems

More from this Author324

Problem Tags

Community Treasure Hunt

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

Start Hunting!