# Problems

51 – 100 of 132
 Problem Title Likes Solvers Difficulty

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

Created by: ChrisR

0

7

#### Problem 56190. Split Even Number Into Two Primes

Created by: Ben Placek

Tags math, primes

4

106

#### Problem 47843. Compute the arithmetic derivative of integers

Created by: ChrisR

0

17

#### 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

2

12

#### Problem 896. Sophie Germain prime

Created by: Aurelien Queffurust

3

627

#### Problem 52639. Determine whether a number is unprimeable

Created by: ChrisR

3

14

#### Problem 47950. Test the generalized Legendre conjecture

Created by: ChrisR

0

13

#### Problem 55275. List the semiprimes

Created by: ChrisR

0

8

Created by: HH

1

6

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

Created by: ChrisR

1

6

#### Problem 45964. Compute the nth Pythagorean prime

Created by: ChrisR

1

24

#### 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

1

9

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

Created by: ChrisR

1

14

#### Problem 58018. List the Fermi-Dirac primes

Created by: ChrisR

2

4

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

Created by: ChrisR

1

12

Created by: goc3

7

430

#### Problem 2337. Sum of big primes without primes

Created by: Jean-Marie Sainthillier

3

135

#### Problem 46047. Identify Wagstaff primes

Created by: ChrisR

Tags primes

2

28

#### Problem 47793. Find the smallest prime with n inside

Created by: ChrisR

3

16

#### Problem 52584. Easy Sequences 9: Faithful Pairs

Created by: Ramon Villamangca

1

16

#### Problem 52881. List the cuban primes

Created by: ChrisR

1

8

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

Created by: yurenchu

3

56

#### Problem 2340. Numbers spiral diagonals (Part 1)

Created by: Jean-Marie Sainthillier

3

171

#### Problem 1096. Largest Twin Primes

Created by: Des Mc Manus

Tags primes

3

556

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

Created by: ChrisR

1

10

#### Problem 241. Project Euler: Problem 7, Nth prime

Created by: Doug Hull

17

1284

#### Problem 42914. Counting the Grand Primes

Created by: John D'Errico

3

40

#### Problem 54700. Leyland Primes

Created by: Dyuman Joshi

1

5

#### Problem 46099. Identify full reptend primes

Created by: ChrisR

0

11

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

Created by: ChrisR

4

13

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

Created by: Ramon Villamangca

1

23

#### Problem 47833. List the delete-a-digit primes

Created by: ChrisR

3

18

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

Created by: elias GR

Tags primes, factors

4

426

#### Problem 51241. Compute home primes in a given base

Created by: ChrisR

0

9

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

Created by: Ramon Villamangca

1

5

#### Problem 51758. List Proth primes

Created by: ChrisR

Tags primes

1

10

Created by: goc3

5

517

#### Problem 52669. Count the primes in Collatz sequences

Created by: ChrisR

1

13

#### Problem 47518. Play Outside In with primes

Created by: ChrisR

1

8

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

Created by: ChrisR

1

9

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

Created by: ChrisR

3

14

#### Problem 48075. Play PRIMEGAME

Created by: ChrisR

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

5140

Created by: CXD

1

6

#### Problem 57477. Solve an equation involving primes and fractions

Created by: ChrisR

2

4

#### Problem 52784. Easy Sequences 38: Prime Number Delta

Created by: Ramon Villamangca

1

4

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

Created by: Richard Zapor

2

14

#### Problem 46582. Find jumping medalists

Created by: ChrisR

3

14

51 – 100 of 132