已解决

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...

1 year 前

已解决

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...

1 year 前

问题

Determine whether a number is a seesaw number
Cody Problem 60957 dealt with balanced primes. In that case, balance was measured in terms of the average of primes around a giv...

1 year 前 | 1 | 8 个解题者

已解决

Chek the Delta = 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...

1 year 前

问题

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 ...

1 year 前 | 3 | 9 个解题者

已解决

Baye's theorem on conditional probability
Let the given probabilities Compute the output probability

1 year 前

问题

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 ...

1 year 前 | 4 | 10 个解题者

已解决

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

1 year 前

问题

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...

1 year 前 | 1 | 8 个解题者

已解决

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 ...

1 year 前

问题

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...

1 year 前 | 2 | 9 个解题者

已解决

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 ...

1 year 前

已解决

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 : ...

1 year 前

已解决

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

1 year 前

已解决

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

1 year 前

问题

Compile evidence for the Carmichael totient conjecture
The totient function counts the positive integers up to that are relatively prime to . The Carmichael totient conjecture state...

1 year 前 | 2 | 7 个解题者

已解决

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

1 year 前

已解决

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

1 year 前

已解决

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

1 year 前

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Primes 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...

1 year 前

已解决

Find the first occurence of a given gap between two consecutive prime numbers
Given a gap = p' - p between the two consecutive prime numbers p and p', find its first occurence, f. For examples : If , f=...

1 year 前

已解决

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

1 year 前

已解决

Breaking up a chocolate bar
You've got a chocolate bar of size , and you want to break it up into bite-sized () pieces. How many steps are required to do th...

1 year 前

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The cake is a lie...
You're hosting a birthday party with a large number of screaming children. Fortunately, you have a gigantic sheet cake in front...

1 year 前

已解决

Dominant Matrix - 02
It is a follow-up of the problem 55995. There, you found out whether a matrix is diagonally dominant or not. In this problem, y...

1 year 前

问题

Classify triangles as acute, obtuse, or right
In an acute triangle, the three interior angles are acute, or smaller than 90 degrees. In an obtuse triangle, one angle is obtus...

1 year 前 | 0 | 11 个解题者

问题

Compute the antisigma function
The sum of divisors function, or , is the sum of the numbers that divide . The antisigma function is the sum of numbers less tha...

1 year 前 | 0 | 10 个解题者

已解决

Symmetric Pair
Given an (n, 2) matrix, remove any symmetric pairs from the matrix. Keep the first occurrence. (2, 3) and (3, 2) are considere...

1 year 前

已解决

Pairs with Given Sum
Given an array of integers and a target sum, return all unique pairs whose sum is equal to the target. The output should be a ma...

1 year 前

已解决

Last Duplicate
Given an array of integers, find the last duplicate element — that is, the element whose second occurrence appears latest in the...

1 year 前