HiveBrain v1.2.0
Get Started
← Back to all entries
patternMinor

Kolmogorov complexity of a sequence of prime numbers

Submitted by: @import:stackexchange-cs··
0
Viewed 0 times
numberssequenceprimecomplexitykolmogorov

Problem

Let's say $p_1, p_2, p_3, \ldots $ is the increasing sorted sequence of all prime numbers. Prove that there exists a constant $n_0 \in \mathbb{N}$, so that for all $n \ge n_0$:
$$K(p_n) < \log_2(p_n) − 2.$$
Hint: Prime number theorem: $p_n \in \Theta (n \ln n)$.

I think, I could have a program A, which generates $p_n$ in $n\ln n$. I could just give A the index of my prime number and it would generate it.

Another idea of mine was to prove it by contradiction and assume the opposite is true but I can't really make that work.
My biggest problem is that I can't find an upper limit to the representation of prime numbers and start from there. Normally I'd just use the factorization for integers…

Any help is appreciated!

Solution

Since we can generate $p_n$ given $n$, $K(p_n) \leq K(n) + O(1) \leq \log_2 n + O(1)$. The prime number theorem implies that $p_n = \Theta(n\ln n)$, and so $\log_2(p_n) = \log_2 n + \log_2\log_2 n \pm O(1)$. You take it from here.

Context

StackExchange Computer Science Q#69719, answer score: 3

Revisions (0)

No revisions yet.