Questions tagged [primes]

For challenges about identifying and manipulating prime numbers

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Print/Output all positive numbers in which every multi-digit substring in its decimal representation is also prime.

Task Your task is to print or output all positive numbers in which every multi-digit substring in its decimal representation is also prime. If the number has at least 2 digits, this would imply that ...
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Is this number a prime?

Believe it or not, we do not yet have a code golf challenge for a simple primality test. While it may not be the most interesting challenge, particularly for "usual" languages, it can be nontrivial in ...
376 views

Do you know the book Murderous Maths, in the Horrible Science series? In the book, the Laplace Princess' "ridiculous" cipher might be interesting enough and simple enough to be a code-golf challenge. ...
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Some Prime Peerage

(Randomly inspired by https://mathoverflow.net/q/339890) (Related: 1, 2) Given an input list of distinct prime numbers (e.g., [2, 5, 7]), and a integer ...
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Find Primes in Pi

Primes are everywhere... they hide inside Pi 3.1415926535897932384626433832795028841971693993751 Let's get those primes! The Challenge Given as input an integer ...
3k views

Bertrand's Primes

Bertrand's Postulate states that for every integer n ≥ 1 there is at least one prime p such that n < p ≤ 2n. In order to verify this theorem for n < 4000 ...
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Find the Smoothest Number

Your challenge is to find the smoothest number over a given range. In other words, find the number whose greatest prime factor is the smallest. A smooth number is one whose largest prime factor is ...
2k views

Shortest code to find next prime palindrome

I was trying to find the shortest code possible that given a number n, returns the next prime palindrome number (limited to below 100000). If the number itself is a prime palindrome, the code should ...
4k views

The program that will find the next prime number

Intro: You accidentally corrupted the flow of time with a device you made for fun, that turned out to be a time machine. As a result, you got pushed to the far future. You realized that computing, ...
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Is this a consecutive-prime/constant-exponent number?

A while ago, I had a look at the prime factorization of 27000: 27000 = 23 × 33 × 53 There are two special things about that: consecutive-prime: The primes are consecutive: 2 is the ...
2k views

Prime or highest factor

Challenge: Given an array of non-negative whole numbers numbers in the range of 0 to Infinity, Check whether all of them are primes or not. (You can take input as ...