Isolating Critical Cases for Reciprocals Using Integer Factorization

On the WZ Factorization of the Real and Integer Matrices

The textit{QIF}  (Quadrant Interlocking Factorization) method of Evans and Hatzopoulos solves linear equation systems using textit{WZ}  factorization. The  WZ factorization can be faster than the textit{LU} factorization  because,  it performs the simultaneous evaluation of two columns or two rows. Here, we present a  method for computing the real and integer textit{WZ} and  textit{ZW} factoriz...

Curious Continued Fractions, Nonlinear Recurrences, and Transcendental Numbers

We consider a family of integer sequences generated by nonlinear recurrences of the second order, which have the curious property that the terms of the sequence, and integer multiples of the ratios of successive terms (which are also integers), appear interlaced in the continued fraction expansion of the sum of the reciprocals of the terms. Using the rapid (double exponential) growth of the ter...

On Square-Free Numbers

In the article the formal characterization of square-free numbers is shown; in this manner the paper is the continuation of [19]. Essentially, we prepared some lemmas for convenient work with numbers (including the proof that the sequence of prime reciprocals diverges [1]) according to [18] which were absent in the Mizar Mathematical Library. Some of them were expressed in terms of clusters’ re...

On the Middle Prime Factor of an Integer

Given an integer n ≥ 2, let p m (n) denote the middle prime factor of n. We obtain an estimate for the sum of the reciprocals of p m (n) for n ≤ x.

On sums involving reciprocals of the largest prime factor of an integer II