How to resolve the algorithm Cullen and Woodall numbers step by step in the Mathematica/Wolfram Language programming language
How to resolve the algorithm Cullen and Woodall numbers step by step in the Mathematica/Wolfram Language programming language
Table of Contents
Problem Statement
A Cullen number is a number of the form n × 2n + 1 where n is a natural number. A Woodall number is very similar. It is a number of the form n × 2n - 1 where n is a natural number. So for each n the associated Cullen number and Woodall number differ by 2. Woodall numbers are sometimes referred to as Riesel numbers or Cullen numbers of the second kind.
Cullen primes are Cullen numbers that are prime. Similarly, Woodall primes are Woodall numbers that are prime. It is common to list the Cullen and Woodall primes by the value of n rather than the full evaluated expression. They tend to get very large very quickly. For example, the third Cullen prime, n == 4713, has 1423 digits when evaluated.
Let's start with the solution:
Step by Step solution about How to resolve the algorithm Cullen and Woodall numbers step by step in the Mathematica/Wolfram Language programming language
The provided Wolfram code snippet defines two functions, CullenNumber
and WoodallNumber
, and uses them to find the first five prime Cullen numbers and the first 12 prime Woodall numbers.
Here's a detailed breakdown of the code:
-
Function Definitions:
CullenNumber[n]
: This function calculates the Cullen number for a given integern
. The Cullen number is defined asn * 2^n + 1
.WoodallNumber[n]
: This function calculates the Woodall number for a given integern
. The Woodall number is defined asn * 2^n - 1
.
-
Listable Attributes: The
Listable
attribute is set for bothCullenNumber
andWoodallNumber
functions. This attribute allows these functions to be applied to lists or arrays element-wise. -
Finding Prime Cullen Numbers: The code finds the first five prime Cullen numbers using a loop:
- It starts with
i = 1
and increments it until it finds five prime Cullen numbers. - For each
i
, it calculates the corresponding Cullen numberCullenNumber[i]
and checks if it is prime usingPrimeQ[CullenNumber[i]]
. - If the Cullen number is prime, it appends the value of
i
to the listcps
(Cullen Prime Sequence). - The loop breaks when the length of
cps
reaches 5, indicating that five prime Cullen numbers have been found.
- It starts with
-
Finding Prime Woodall Numbers: The code follows a similar process to find the first 12 prime Woodall numbers:
- It starts with
i = 1
and increments it until it finds 12 prime Woodall numbers. - For each
i
, it calculates the corresponding Woodall numberWoodallNumber[i]
and checks if it is prime usingPrimeQ[WoodallNumber[i]]
. - If the Woodall number is prime, it appends the value of
i
to the listwps
(Woodall Prime Sequence). - The loop breaks when the length of
wps
reaches 12, indicating that 12 prime Woodall numbers have been found.
- It starts with
-
Printing the Results: Finally, the code prints the lists
cps
andwps
to display the first five prime Cullen numbers and the first 12 prime Woodall numbers, respectively.
Source code in the wolfram programming language
ClearAll[CullenNumber, WoodallNumber]
SetAttributes[{CullenNumber, WoodallNumber}, Listable]
CullenNumber[n_Integer] := n 2^n + 1
WoodallNumber[n_Integer] := n 2^n - 1
CullenNumber[Range[20]]
WoodallNumber[Range[20]]
cps = {};
Do[
If[PrimeQ[CullenNumber[i]],
AppendTo[cps, i];
If[Length[cps] >= 5, Break[]]
]
,
{i, 1, \[Infinity]}
]
cps
wps = {};
Do[
If[PrimeQ[WoodallNumber[i]],
AppendTo[wps, i];
If[Length[wps] >= 12, Break[]]
]
,
{i, 1, \[Infinity]}
];
wps
You may also check:How to resolve the algorithm Fast Fourier transform step by step in the Stata programming language
You may also check:How to resolve the algorithm Middle three digits step by step in the Lambdatalk programming language
You may also check:How to resolve the algorithm Roman numerals/Encode step by step in the J programming language
You may also check:How to resolve the algorithm Host introspection step by step in the XPL0 programming language
You may also check:How to resolve the algorithm RPG attributes generator step by step in the Ksh programming language