Partitioning the set of natural numbers into Mersenne trees and into arithmetic progressions; Natural Matrix and Linnik's constant

Abstract

We partition a series of natural numbers into infinite number sequences. We consider two partitioning options: (a) a forest of unary trees with recurrence formula of Mersenne numbers, and (b) a set of arithmetic progressions with difference $2^k$. Every tree starts with an even number, and any even number starts a certain tree. In the partitioning into arithmetic progressions, each progression starts with a Mersenne number, and each Mersenne number is the beginning of a particular arithmetic progression. Unary trees starting from some term are contained in OEIS A036991 (compact Dyck path codes), so we consider A036991 as a backbone of the partitions. In particular, we prove the existence of an arithmetic progression of any length in A036991. As a result of the partitions, we obtain a Natural Matrix with a packing function that captures the bijection between the set of natural numbers and the set of ordered pairs of natural numbers. In Natural Matrix, the even natural numbers are located on the $x$-axis, so the selection of primes in the considered arithmetic progressions is greatly simplified. A method for proving the infinity of primes in A036991 is proposed. In this regard, an attempt is made to reduce the Linnik's constant to $2$.