Results: **5**

#### About one way of determination of **prime** numbers

The method of finding **prime** numbers without computer calculation is shown. Subsets P1 = {6k1 – 1}, P2 = {6k2 + 1}, Q1 = {6j1 – 1}, Q2 = {6j2 + 1} are considered, where P1 È P2 are all **prime** numbers p ≥ 5; Qi are all odd composite numbers of such form. Subsets Ai = {ki},...

#### About some regularities in a structure of subsets of **prime** numbers

It is shown that the first four **primes** 2, 3, 5, 7 generate finite subsets of **primes**, assuming the principle of interchangeability. In is established that any **prime** p(11 p 41, p 19), added together with two preceding **primes** generates a **prime** and that any **prime** p (5 p 31, p 13),...

#### Subsets of **prime** numbers in the generalized arithmetical progressions

... progression of the power k and difference d is given. For k 1,7 formulas of nth member of such progressions and for k 1, 2, 3 formulas for the sum of the first n its members are obtained. Progressions ( ) , k p d M with the first member **prime** number p and difference being a positive even number d 2m (m ) are considered. Such progressions define subsets ( )
, , k h p d M of h **prime** numbers (h ). For k 20, p 95467, d 108 all subsets (1) h,p,d M with h 15 **prime** ...

#### A study into the effectiveness of modifying primer protective layers in St3 steel in case of corrosion initiated by Aspergillus niger

Mould fungi are of particular interest as metal destroying microorganisms. This paper presents the results of a study on a number of organic compounds as St3 steel corrosion inhibitors and fungicides against the Aspergillus niger. Electrochemical, microbiological and gravimetric analyses helped increase the protective action of modified primer on steel corroding under the effect of Aspergillus niger. 1. Кузнецов М. В. Противокоррозионная защита трубопроводов...

#### How to extract formulas from Pascal's triangle to find all **primes**

... infinite set of numerical properties of a right-angled Pascal triangle is confirmed and the main results of finding its numerical discriminant are given. Exactly, the numerical properties of the truncated Pascal triangle for the direct finding of all **primes** are found.
Sherban V. L.
Pascal triangle, Fibonacci numbers, **prime** numbers, recurrent sequences
23-39