Solved

Prime number check (★★)
One way to see if a number x is prime is to compute the remainders obtained when dividing x by all integers from 2 to √(x). If x...

1 día ago

Solved

That's some divisor you've got there...
Given a positive integer x, calculate the sum of all of the divisors of the number. Please include the number itself in your fi...

1 día ago

Solved

Find prime number couples
Given a vector a, which will always contain at least one pair of prime numbers couple, return a matrix called 'couple' in which ...

1 día ago

Solved

Sort the prime numbers in each row of a matrix
Considering a 3x3 matrix A, sort the prime numbers of each row in ascending order. For exemple: input A=[5 8 2 4; ...

1 día ago

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Given a number N, find the smallest prime P>N
Given a number N, find the smallest prime P greater than N. For example: If N=10 then P=11. If N=13 then P=17.

1 día ago

Solved

Find my secret function I
If give my function a x value it will give me a y value, so find the secret of it: Examples: input x=[2 5 6 8 9] ---- >>> o...

1 día ago

Solved

Given a base n, find the y values less or equal than 100(without 1), such that they will never produce a periodic number if we divide any whole number between some of them
A periodic number depends on the base b where we are working. So, for example the number 2/3 in decimal base is periodic(0.666...

1 día ago

Solved

Determina si el número es primo
Primero, antes que nada: ¿Qué es un número primo? Un número primo es cualquier número que solamente se puede dividir por 1 y ...

1 día ago

Solved

Is this triangle right-angled?
Given any three positive numbers a, b, c, return true if the triangle with sides a, b and c is right-angled. Otherwise, return f...

1 día ago

Solved

Compute the Sequence of the Day
A sequence starts with 1 and 2, and each subsequent term is the sum of the digits of the product of the previous two terms. As a...

2 días ago

Problem

Easy Sequences 54: Product of Products of Proper Divisors
For a given positive integer , we are asked to evaluate the following summation: This is equivalent to finding t...

3 días ago | 0 | 1 solver

Solved

Tribute to Ramanujan
The nth taxicab number, denoted as T(n), is defined as the smallest number that can be expressed as a sum of two positive algebr...

7 días ago

Solved

Carmichael Number

7 días ago

Solved

Sum of Dividend Digits
Find the smallest number that consist of only number 1's (e.g. 11111111111) which satisfy a given divisor and remainder. Then re...

8 días ago

Solved

Compute Khinchin's constant
Khinchin's constant K_0 = 2.684542001... (also written "Khintchine's constant") has the amazing property that it is the limiting...

8 días ago

Solved

Wythoff Sequence
Find the lower Wythoff sequence up to n. For more information, <https://oeis.org/A000201>

8 días ago

Solved

Frobenius McNugget Factorization
Mr. Frobenius McNugget is a peculiar man. As you might expect, he likes to eat Chicken McNuggets. But his love of number the...

8 días ago

Solved

Amicable pair
Amicable numbers are two different numbers such that the sum of the proper divisors of each is equal to the other number. For...

8 días ago

Solved

Sieve of Eratosthenes
Find the nth lucky prime number. <https://planetmath.org/luckyprime> can u find a way for large n?

9 días ago

Solved

Integer complexity (Large numbers)
Inspired by <http://www.mathworks.com/matlabcentral/cody/problems/42831-integer-complexity Problem 42831>, this problem aims to ...

9 días ago

Solved

Integer complexity
Given an array, n, of positive integers, return an array, c, of the same size, in which each element is the <https://en.wikipedi...

11 días ago

Solved

Number of even divisors of a given number
Given a Number n, return the number of its even divisors without listing them. example: n=14 ; EvenDivisors={2,14} ; y=2 ...

11 días ago

Solved

<https://oeis.org/A087061 OEIS link for a description of lunar arithmetic> Simply take the larger digit. Example 1: ...

12 días ago

Solved

Whole Number Un-Concatenator
Write a function that accepts an integer and an index digit and returns a vector containing two integers which are the leading a...

13 días ago

Solved

Better Index Number
Let's say you want to save many, many files and append these files with a certain sortable index number. As you probably know, y...

13 días ago

Solved

The last non-zero digit of a factorial
For given positive integer n, what is the last non-zero digit of n!? Example: factorial(11) = 39916800 Last non-zero d...

13 días ago

Problem

Easy Sequences 53: Greatest Proper Divisor
The greatest proper divisor () of an integer is the largest integer , such that and . Furthermore, we define: . Below is the...

13 días ago | 1 | 2 solvers