Split up $n \in \mathbb{N}$ into sum of naturals with maximum LCM
Question:
Given some natural number, we can of course split it up into various sums of other naturals (e.g. $7 = 6 + 1 = 1 + 4 + 2 = \ldots$)
More precisely, for $n \in \mathbb{N}$, we can a find distribution sequence (or partition) $s_0,\ldots,s_u \in \mathbb{N}$ with
$$\sum_{i=0}^{u}s_i = n$$
Now how can I find the partition $s$ for which the overall least common multiple of all elements is maximal. Or differently formulated the maximum product of distinct prime factors of all elements.
Example:
$$ 7 \mapsto (3, 4); \Pi_{lcm} = 12 $$ $$ 7 \mapsto (1, 2, 4); \Pi_{lcm} = 4$$ $$ \ldots $$
Here, the first solution is the desired one.
Background:
The background of my question is: How can I split up a sequence/string into contiguous subsequences that, when repeated and zipped together, will yield the longest possible resulting sequence.
For the above example, I could split up a string of length $7$ in the following way:
7: abcdefg 7: abcdefg
I II
1: aaaa 3: abcabcabcabc
2: bcbc 4: defgdefgdefg
4: defg
Of course, using the second distribution, the resulting sequence has a much greater period.
So:
What algorithm/approach can I use to solve this problem and maximize the product? Is this some known problem and how complex would calculating a solution be? It's not NP, I hope?!
Edit: Partial solution
As @KennyTM pointed out in the comments, Landau's function $g$ describes the maximum LCM, i.e. $g(7) = 12$.
So this actually becomes: How to actually produce the partition? Does knowledge of $g(x)$ help here, maybe for a dynamic programming solution?
Solution 1:
The blog post here describes somebody else's efforts at coding this up. He gets an improvement over the naive approach by using some nice internal structure of the problem.