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System of equations
Find a solution to a system of equations represented by a |n| by |n+1| matrix. For instance, [ 2 0 4; => 2*x = 4 ...

1 month ago

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Project Euler: Problem 1, Multiples of 3 and 5
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23...

1 month ago

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Column norms of a matrix
Given a matrix M, return a vector y such that for each k y(k)=norm(M(:,k)) (y(k) is the Euclidean norm of the k-th col...

1 month ago

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Subtract integers and add doubles
Create a function that subtracts a from b if a and b are integers and adds them if they are floats.

1 month ago

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Nearest Numbers
Given a row vector of numbers, find the indices of the two nearest numbers. Examples: [index1 index2] = nearestNumbers([2 5 3...

2 months ago

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Find the first occurence of a given gap between two consecutive prime numbers
Problem statement Given a gap = p' - p between the two consecutive prime numbers p and p', find its first occurence, f. E...

2 months ago

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Check the integers additive decomposition conjecture
Problem statement A conjecture (I rediscovered ?) related to Goldbach's one states that every integer above 2 can be written ...

2 months ago

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Check p² = 24k + 1, p > 3, the 'golden prime squares' equation
Historical context In december 2023, I / Nicolas Douillet was working on prime squares properties and I found* the formula : ...

2 months ago

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Euclid primes
Historical context Euclid, the greek mathematician proved at his time that the prime numbers set is an infinite. By the way he ...

2 months ago

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Fermat primes
Historical context The french mathematician Pierre de Fermat found the formula to find some prime numbers. He thought / co...

2 months ago

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Ulam primes first formula
Historical context The polish-american mathematician Stanislaw Ulam found the formula to give the first 760 prime numbers ...

2 months ago

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Ulam primes second formula
Historical context The polish-american mathematician Stanislaw Ulam found the formula to give some prime numbers not given...

2 months ago

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Euler primes
Historical context The great swiss mathematician Leonhard Euler found the formula to give some prime numbers. Problem...

2 months ago

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Frequencies of prime gaps
Problem statement Given two positive integers n and , write a function which computes the frequency of the gap between two ...

2 months ago

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Prime numbers which are the difference of two consecutive cubes
Problem statement Given a positive integer n greater than 2, find the prime numbers less or equal to n and which are the diff...

2 months ago

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expand intervals vol.2
Similar to problem <http://www.mathworks.co.uk/matlabcentral/cody/problems/2528 2528>. This is a more general case, when bounds ...

2 months ago

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remove single elements
Given a vector of integers, remove the elements that have appeared only once. The output elements should be in exact order as th...

2 months ago

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expand intervals vol.3
This is the next problem after <http://www.mathworks.co.uk/matlabcentral/cody/problems/2528 2528> and <http://www.mathworks.co.u...

2 months ago

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Make a rainbow matrix (follow-up to checkerboard matrix)
Given an integer n, make an n-by-n matrix as shown below. The a(1,1) should be 0. As we move away from the top-left, the number ...

2 months ago

Solved

Linear primes p' = mp + n
Problem statement List the prime numbers of the form p' = mp + n for a given (m,n) couple and such that p' < k, k positive in...

2 months ago

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Check Legendre's conjecture
Context and problem statement Legendre's conjecture states for a given positive integer n, there always exists at least one pri...

2 months ago

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Check Bertrand-Chebyshev's theorem about prime numbers
Historical context Bertrand's postulate, also later known as Chebyshev's theorem, is a very important theorem in number theory ...

2 months ago

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Chek the Delta = p' - p = 6k gap theorem about arithmetic progressions in the prime number set
Context In the prime numbers set there are some arithmetic progressions (sequences of three or more consecutive prime number...

2 months ago

Solved

List the complementary / symetric prime couples
Problem statement For a given positive integer n, provide the prime couples (p,p') such that p + p' = 10^n. NB : a number li...

2 months ago

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Sum the 'edge' values of a matrix
Sum the 'edge' values of an input matrix (the values along the perimeter). Example [1 2 3 4 5 6 7 8 9] Output = ...

2 months ago

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Pattern Sum
Write a function which receives two single digit positive integers, (k and m) as parameters and calculates the total sum as: k...

2 months ago

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Flipping
Write code that can reverse the vector without using any sort of loop. Example Given the input vector A = [ 1 2 3 4 5...

2 months ago

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Flip the diagonal values
Write a program that flip the elements of main diagonal , upper and lower diagonal values of a sqare matrix. For example if a ...

2 months ago

Solved

Flip the bit
Given an input character string (e.g. '1001'), return a character string with the bits flipped ('0110').

2 months ago

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Flipping a Matrix
Flipping matrix up and down. If a central row is exists, leave it, and flip remaining rows. Example Mat = magic(3) ...

2 months ago