Cody

Problems

51 – 100 of 136
Problem Title
Likes
Solvers
Difficulty

Problem 51312. Count the square-full divisors of a number

Created by: ChrisR

Tags primes, number theory, sequence

0

7

Problem 49733. Solve the arithmetic differential equation D(n) = n

Created by: ChrisR

Tags primes, integers, arithmetic derivative integers

0

10

Problem 43087. Move if I am Optimus Prime

Created by: Jamil Kasan

Tags primes, jokes

8

34

Problem 52288. List Honaker primes

Created by: ChrisR

Tags primes, digit sum

2

12

Problem 52639. Determine whether a number is unprimeable

Created by: ChrisR

Tags primes, project euler

3

14

Problem 47950. Test the generalized Legendre conjecture

Created by: ChrisR

Tags primes, conjecture

0

13

Problem 45964. Compute the nth Pythagorean prime

Created by: ChrisR

Tags primes, pythagoras, number theory

1

25

Problem 896. Sophie Germain prime

Created by: Aurelien Queffurust

Tags prime, primes, sophie germain

3

730

Problem 46057. Find the last non-zero digit in a primorial

Created by: ChrisR

Tags primes, number theory, primorial

1

14

Problem 52956. Compute the largest number whose prime factors sum to n

Created by: ChrisR

Tags primes, sequence, integer complexity

1

6

Problem 55275. List the semiprimes

Created by: ChrisR

Tags primes, number theory, sequence

0

8

Problem 56308. Korselt's Criterion

Created by: HH

Tags primes, number theory, carmichael

1

6

Problem 51198. Find pairs of primes with the same digit sum and a specified separation

Created by: ChrisR

Tags primes, sequence, digit sum

1

12

Problem 44305. 5 Prime Numbers

Created by: goc3

Tags prime, primes, string

7

431

Problem 46047. Identify Wagstaff primes

Created by: ChrisR

Tags primes

2

28

Problem 2337. Sum of big primes without primes

Created by: Jean-Marie Sainthillier

Tags primes, project euler, eratosthenes

3

113

Problem 56190. Split Even Number Into Two Primes

Created by: Ben Placek

Tags math, primes

5

161

Problem 47843. Compute the arithmetic derivative of integers

Created by: ChrisR

Tags primes, integers, arithmetic derivative

0

19

Problem 47793. Find the smallest prime with n inside

Created by: ChrisR

Tags primes, strings, sequence

3

16

Problem 52584. Easy Sequences 9: Faithful Pairs

Created by: Ramon Villamangca

Tags easy, sequences, primes

1

16

Problem 58018. List the Fermi-Dirac primes

Created by: ChrisR

Tags primes, number theory

2

5

Problem 44403. Goldbach's marginal conjecture - Write integer as sum of three primes

Created by: yurenchu

Tags primes, goldbach conjecture

3

58

Problem 52881. List the cuban primes

Created by: ChrisR

Tags primes, project euler, sequence

1

8

Problem 2340. Numbers spiral diagonals (Part 1)

Created by: Jean-Marie Sainthillier

Tags primes, project euler, spiral

3

179

Problem 1096. Largest Twin Primes

Created by: Des Mc Manus

Tags primes

3

662

Problem 44849. 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

Created by: Fabio Squizzato

Tags primes, linear algebra, basic matlab

1

11

Problem 46594. Create a sequence of primes p such that p > n π(p)

Created by: ChrisR

Tags primes, sequence

1

10

Problem 241. Project Euler: Problem 7, Nth prime

Created by: Doug Hull

Tags primes, projecteuler

17

1371

Problem 46099. Identify full reptend primes

Created by: ChrisR

Tags primes, number theory

0

11

Problem 54700. Leyland Primes

Created by: Dyuman Joshi

Tags primes, number theory

1

5

Problem 49778. Determine whether a number is a prime self number

Created by: ChrisR

Tags primes, kaprekar

4

13

Problem 59050. Determine whether a number is a Higgs prime

Created by: ChrisR

Tags primes, sequence, subset

0

4

Problem 52497. Easy Sequences 3: Prime 44-number Squares

Created by: Ramon Villamangca

Tags easy, sequences, primes

1

23

Problem 47833. List the delete-a-digit primes

Created by: ChrisR

Tags sequences, primes

3

18

Problem 365. Numbers with prime factors 2, 3 and 5.

Created by: elias GR

Tags primes, factors

4

458

Problem 51241. Compute home primes in a given base

Created by: ChrisR

Tags primes, sequence, base conversion

0

9

Problem 42914. Counting the Grand Primes

Created by: John D'Errico

Tags prime, primes, intersect

3

44

Problem 2910. Mersenne Primes vs. All Primes

Created by: goc3

Tags primes, comparison, powers

5

574

Problem 52789. Easy Sequences 26: Prime-Integer Line Segments

Created by: Ramon Villamangca

Tags easy, primes, geometry

1

5

Problem 51758. List Proth primes

Created by: ChrisR

Tags primes

1

10

Problem 52669. Count the primes in Collatz sequences

Created by: ChrisR

Tags primes, sequence, another collatz problem

1

14

Problem 46087. Investigate the frequency of last non-zero digits of primorials

Created by: ChrisR

Tags primes, number theory, primorial

1

9

Problem 47518. Play Outside In with primes

Created by: ChrisR

Tags primes, puzzle, sequence

1

8

Problem 45994. Investigate the frequency of last digits of prime numbers

Created by: ChrisR

Tags primes, number theory

3

14

Problem 48075. Play PRIMEGAME

Created by: ChrisR

Tags primes, sequence, conway

2

12

Problem 49783. List the good primes

Created by: ChrisR

Tags primes

1

13

Problem 60. The Goldbach Conjecture

Created by: Cody Team

Tags primes

57

5364

Problem 659. How long is the longest prime diagonal?

Created by: Ned Gulley

Tags primes, spiral, diagonal

14

385

Problem 1697. Make a Pandiagonal Prime Magic Square: 11 x 11

Created by: Richard Zapor

Tags primes, magic square, pandiagonal

2

14

Problem 46582. Find jumping medalists

Created by: ChrisR

Tags primes, sorting, number theory

3

14
51 – 100 of 136