Solved

List the near-square primes, p = n² + 1 (Landau's 4th problem)
Historical context At the 1912 International Congress of Mathematicians, Edmund Landau listed four basic problems about prime...

6 months ago

Solved

List primes which are the sum of two consecutive lower primes plus minus one
Problem statement Some prime numbers can be written as the sum of two consecutive lower primes plus / minus one : Like t...

6 months ago

Solved

Check p = 6n +/- 1, the generic formula for odd prime numbers greater than 3
Problem statement For all odd prime number p greater than 3, there exists a positive integer n, such that p = 6n +/- 1 : ...

6 months ago

Solved

Check p = 4n +/- 1, the generic formula for odd prime numbers
Problem statement For all odd prime number p, there exists a positive integer n, such that p = 4n +/- 1 : Check this f...

6 months ago

Solved

Determine if LTI system with feedback control is stable
Linear timeiinvariant systems can be represented by the differential equation , where is an matrix, is an vector representing...

6 months ago

Solved

Monkey and the Peaches
A monkey picked a certain number of peaches on the first day. Each day, the monkey eats half of the remaining peaches plus one ...

6 months ago

Solved

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...

6 months ago

Solved

List balanced primes
A balanced prime of order is one that equals the average of the primes before it and the primes after it. For example, 79 is ...

6 months ago

Solved

P(girl likes you | she smiled at you)
Compute the probability Given the input probabilities

6 months ago

Solved

List mean-of-2 primes
The prime number 53 is the average of the first prime before it (47) and the first prime after it (59), and the prime number 11 ...

6 months ago

Solved

My wife's logic
Its is always the opposite of the causality law, that is to say the opposite of the implication relationship in math/logic terms...

6 months ago

Solved

List even numbers whose Goldbach partition does not use the largest prime
The strong Goldbach conjecture says that every even number greater than 2 can be expressed as a sum of two prime numbers—that is...

7 months ago

Solved

Extra colors
Context In the RGB color system used by Matlab, the color is a 1 x 3 / row vector [R G B] with each value/component R, G, B in ...

7 months ago

Solved

Give the Shortest Path Through The Maze
*Description* The purpose of this problem is to give the shortest path through a maze. The maze will be provided in a codifie...

7 months ago

Solved

What are the odds?
Two numbers, A and B are drawn randomly and uniformly on [-R,R]. What is the probability that A*B < A+B. Your function should ...

7 months ago

Solved

Find the longest runs of primes generated by polynomials
Cody Problems 60942, 60943, and 60944 involve polynomials that generate primes. No polynomial can generate only prime numbers, b...

7 months ago

Solved

Subdivide the Segment
Two points, P1 and P2, with integer x-y coordinates are given. These uniquely determine a third point, P0, on the extended line ...

7 months ago

Solved

How many palindromes?
* Given a set of letters, count all possible palindromes, using all of those letters. * For example, if the set is {'A' 'A' 'A'...

7 months ago

Solved

Steal, Share, or Catch
You, I, and a few other characters are going to play a game of *Steal, Share or Catch*. We are going to play it 10,000 times vs...

7 months ago

Solved

Image Processing 002 : Fix Vignetting in a Visible Sensor
The task is to correct image files for Visible scanning sensors that due to errant tolerancing produce vignetted(V) images. The ...

7 months ago

Solved

Magic array teasing num2cell

7 months ago

Solved

arrayfun bomb

7 months ago

Solved

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

7 months ago

Solved

Kurchan 3x3 - Optimal Score
Find an optimal 3x3 Kurchan square, score of 198. A 3x3 Kurchan square has values 1:9.The products of each row, column, diag...

7 months ago

Solved

Check the 'golden prime squares' equation
Historical context In december 2023, I / Nicolas Douillet was working on prime squares properties and I found* the formula : ...

7 months ago

Solved

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

7 months ago

Solved

List the Beatriz numbers
Write a function to find integers less than or equal to an input value that solve the equation . The function gives the sum o...

7 months ago

Solved

Iterate the sum of divisors and totient

7 months ago

Solved

Compute a sum involving the totient over divisors of a number
Write a function to compute the following sum: where is the totient function. The sum is computed over the divisors of (inc...

7 months ago

Solved

Compute the unitary totient of a number
The totient function , the subject of Cody Problems 656 and 50182, gives the number of integers smaller than that are relativel...

7 months ago