The ThreeKPlusOne Package

Version 42
Dummy Authör 3kplusone@dev.null
©right; 2000 The Author.

You can do with this package what you want.

Really.
The 3k+1 Problem
Theory Let k \in &NN; be a natural number. We consider the sequence n(i, k), i \in &NN;, with n(1, k) = k and else n(i+1, k) = n(i, k) / 2 if n(i, k) is even and n(i+1, k) = 3 n(i, k) + 1 if n(i, k) is odd.

It is not known whether for any natural number k \in &NN; there is an m \in &NN; with n(m, k) = 1.

ThreeKPlusOne provides the function to explore this for given n. If you really want to know something about this problem, see or https://www.ku.de/mgf/mathematik/statistik/personen-des-lehrstuhls/prof-dr-guenther-wirsching for more details (and forget this package).
Program In this section we describe the main function of this package. This function computes for a natural number k the beginning of the sequence n(i, k) defined in section . The sequence stops at the first 1 or at n(max, k), if max is given.
gap> ThreeKPlusOneSequence(101); "Sorry, not yet implemented. Wait for Version 84 of the package"