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lai duc


Last seen: circa un anno ago Active since 2021

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Sophie Germain prime
In number theory, a prime number p is a *Sophie Germain prime* if 2p + 1 is also prime. For example, 23 is a Sophie Germain prim...

circa un anno ago

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The Goldbach Conjecture
The <http://en.wikipedia.org/wiki/Goldbach's_conjecture Goldbach conjecture> asserts that every even integer greater than 2 can ...

circa un anno ago

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Find the maximum number of decimal places in a set of numbers
Given a vector or matrix of values, calculate the maximum number of decimal places within the input. Trailing zeros do not coun...

circa un anno ago

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Numbers with prime factors 2, 3 and 5.
Make a function which takes one positive integer n and returns a matrix with the numbers of the form (2^i)*(3^j)*(5^k) which are...

circa un anno ago

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Smith numbers
Return true if the input is a Smith number in base ten. Otherwise, return false. Read about Smith numbers at <http://en.wikipedi...

circa un anno ago

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Make roundn function
Make roundn function using round. x=0.55555 y=function(x,1) y=1 y=function(x,2) y=0.6 y=function(x,3) ...

circa un anno ago

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Rounding off numbers to n decimals
Inspired by a mistake in one of the problems I created, I created this problem where you have to round off a floating point numb...

circa un anno ago

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Matlab Basics - Rounding III
Write a script to round a large number to the nearest 10,000 e.g. x = 12,358,466,243 --> y = 12,358,470,000

circa un anno ago

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Matlab Basics - Rounding II
Write a script to round a variable x to 3 decimal places: e.g. x = 2.3456 --> y = 2.346

circa un anno ago

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Check that number is whole number
Check that number is whole number Say x=15, then answer is 1. x=15.2 , then answer is 0. http://en.wikipedia.org/wiki/Whole_numb...

circa un anno ago

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MATLAB Basic: rounding IV
Do rounding towards plus infinity. Example: -8.8, answer -8 +8.1 answer 9 +8.50 answer 9

circa un anno ago

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MATLAB Basic: rounding III
Do rounding towards minus infinity. Example: -8.8, answer -9 +8.1 answer 8 +8.50 answer 8

circa un anno ago

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MATLAB Basic: rounding II
Do rounding nearest integer. Example: -8.8, answer -9 +8.1 answer 8 +8.50 answer 9

circa un anno ago

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MATLAB Basic: rounding
Do rounding near to zero Example: -8.8, answer -8 +8.1 answer 8

circa un anno ago

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Prime factor digits
Consider the following number system. Calculate the prime factorization for each number n, then represent the prime factors in a...

circa un anno ago

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Generalised Hamming Number
Inspired by Project Euler n°204 and Problem 1308 by James A generalised Hamming number of type n, has no prime factor larger ...

circa un anno ago

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Factorize THIS, buddy
List the prime factors for the input number, in decreasing order. List each factor only once, even if the factorization includes...

circa un anno ago

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Get all prime factors
List the prime factors for the input number, in decreasing order. List each factor. If the prime factor occurs twice, list it as...

circa un anno ago

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Find vampire numbers
A <http://en.wikipedia.org/wiki/Vampire_number vampire number> is a number v that is the product of two numbers x and y such th...

circa un anno ago

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Proper Factors
Generate the proper factors of input integer x and return them in ascending order. For more information on proper factors, refer...

circa un anno ago

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Multiples of a Number in a Given Range
Given an integer factor _f_ and a range defined by _xlow_ and _xhigh_ inclusive, return a vector of the multiples of _f_ that fa...

circa un anno ago

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Circular Primes (based on Project Euler, problem 35)
The number, 197, is called a circular prime because all rotations of the digits: 197, 971, and 719, are themselves prime. The...

circa un anno ago

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Largest Twin Primes
<http://en.wikipedia.org/wiki/Twin_prime Twin primes> are primes p1, p2 = p1 + 2 such that both p1 and p2 are prime numbers. Giv...

circa un anno ago

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Make a vector of prime numbers
Input(n) - length of vector with prime numbers Output(v) - vector of prime numbers Example: * n=1; v=2 * n=3; v=[2 3 5...

circa un anno ago

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Find the next prime number
Find the next prime number or numbers for given n. For example: n = 1; out = 2; or n = [5 7]; out = [7 11]; ...

circa un anno ago

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Mersenne Primes
A Mersenne prime is a prime number of the form M = 2^p - 1, where p is another prime number. For example, 31 is a Mersenne prim...

circa un anno ago

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Find nearest prime number less than input number
Find nearest prime number less than input number. For example: if the input number is 125, then the nearest prime number whi...

circa un anno ago

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Mersenne Primes vs. All Primes
A Mersenne prime (M) is a prime number of the form M = 2^p - 1, where p is another prime number. <https://www.mathworks.com/matl...

circa un anno ago

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Roll the Dice!
*Description* Return two random integers between 1 and 6, inclusive, to simulate rolling 2 dice. *Example* [x1,x2] =...

circa un anno ago

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Vector creation
Create a vector using square brackets going from 1 to the given value x in steps on 1. Hint: use increment.

circa un anno ago

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