A résolu

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...

5 mois il y a

A résolu

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...

5 mois il y a

A résolu

List the twin prime couples
Problem statement The twin prime couples (p,p') are the ones such that p' = p + 2. For a given integer n > 1, list the twin p...

5 mois il y a

A résolu

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 ...

5 mois il y a

A résolu

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 : ...

5 mois il y a

A résolu

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...

5 mois il y a

A résolu

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...

5 mois il y a

A résolu

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...

5 mois il y a

A résolu

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...

5 mois il y a

A résolu

find nth even fibonacci number
1st even fibonacci number=2 ; 2nd even fibonacci number=8 ..

5 mois il y a

A résolu

Find the index of nth maximum of a row vector of real numbers
Given a vector of real numbers x, find the index idx of _n_ th maximum value. If nth maximum occurs more than once, return the i...

5 mois il y a

A résolu

Find the Nth Root of a Given Number
Find the Nth root of a given number x. Examples x = 4096 n = 4 y = 8 x = 625 n = 5 y = 3.6239

5 mois il y a

A résolu

Find the nth composite number.
Everyone heard about the nth prime number. Let's try to find out the nth composite. For example , 1 is the first composite, 10 i...

5 mois il y a

A résolu

Find nth maximum
Find nth maximum in a vector of integer numbers. Return NaN if no such number exists. x = [2 6 4 9 -10 3 1 5 -10]; So ...

5 mois il y a

A résolu

Find the logic and return the nth number
given a sequence of numbers arranged in the following order: A=0,1,3,4,9,10,12,13,27,28,30,31,36,37,...... Write a function th...

5 mois il y a

A résolu

Find the logic and return the nth number (plus)
This problem is the harder version of Problem 61015 given a sequence of numbers arranged in the following order: A=0,1,3,4,9,1...

5 mois il y a

A résolu

find the nth fibonacci number
The Fibonacci sequence is defined as follows: give n, find the nth fibonacci number

5 mois il y a

A résolu

Find nth number
The numbers 2 and 7 are called lucky numbers, an integer containing only the digits 2 and 7 is also called lucky number. The pro...

5 mois il y a

A résolu

find the nth number (plus)
this problem is the harder version of Problem 61014. The numbers 2 and 7 are called lucky numbers, an integer containing only t...

5 mois il y a

A résolu

Sum all integers from 1 to 2^n
Given the number x, y must be the summation of all integers from 1 to 2^x. For instance if x=2 then y must be 1+2+3+4=10.

5 mois il y a

A résolu

Magic is simple (for beginners)
Determine for a magic square of order n, the magic sum m. For example m=15 for a magic square of order 3.

5 mois il y a

A résolu

Make a random, non-repeating vector.
This is a basic MATLAB operation. It is for instructional purposes. --- If you want to get a random permutation of integer...

5 mois il y a

A résolu

Number of 1s in a binary string
Find the number of 1s in the given binary string. Example. If the input string is '1100101', the output is 4. If the input stri...

5 mois il y a

A résolu

Return the first and last characters of a character array
Return the first and last character of a string, concatenated together. If there is only one character in the string, the functi...

5 mois il y a

A résolu

Create times-tables
At one time or another, we all had to memorize boring times tables. 5 times 5 is 25. 5 times 6 is 30. 12 times 12 is way more th...

5 mois il y a

A résolu

Getting the indices from a vector
This is a basic MATLAB operation. It is for instructional purposes. --- You may already know how to find the logical indices o...

5 mois il y a

A résolu

Determine whether a vector is monotonically increasing
Return true if the elements of the input vector increase monotonically (i.e. each element is larger than the previous). Return f...

5 mois il y a

A résolu

Check if number exists in vector
Return 1 if number a exists in vector b otherwise return 0. a = 3; b = [1,2,4]; Returns 0. a = 3; b = [1,2,3]; Returns 1.

5 mois il y a

A résolu

Swap the first and last columns
Flip the outermost columns of matrix A, so that the first column becomes the last and the last column becomes the first. All oth...

5 mois il y a

A résolu

Swap the input arguments
Write a two-input, two-output function that swaps its two input arguments. For example: [q,r] = swap(5,10) returns q = ...

5 mois il y a