# Problems

51 – 100 of 123
 Problem Title Likes Solvers Difficulty

Created by: HH

1

5

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

Created by: ChrisR

0

7

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

Created by: ChrisR

0

15

#### Problem 46060. Identify primorial primes

Created by: ChrisR

1

13

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

Created by: ChrisR

0

11

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

Created by: Jean-Marie Sainthillier

2

151

#### Problem 1096. Largest Twin Primes

Created by: Des Mc Manus

Tags primes

2

393

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

Created by: Ben Placek

Tags math, primes

2

53

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

Created by: ChrisR

1

6

#### Problem 52288. List Honaker primes

Created by: ChrisR

2

11

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

Created by: Ramon Villamangca

1

14

#### Problem 43087. Move if I am Optimus Prime

Created by: Jamil Kasan

Tags primes, jokes

8

34

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

Created by: ChrisR

0

20

#### 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

Created by: goc3

7

426

#### Problem 46047. Identify Wagstaff primes

Created by: ChrisR

Tags primes

2

26

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

Created by: ChrisR

3

12

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

Created by: ChrisR

3

15

#### Problem 55275. List the semiprimes

Created by: ChrisR

0

7

#### Problem 52881. List the cuban primes

Created by: ChrisR

1

8

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

Created by: Doug Hull

14

1092

Created by: goc3

5

352

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

Created by: Jean-Marie Sainthillier

3

164

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

Created by: ChrisR

1

9

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

Created by: yurenchu

3

46

#### Problem 46099. Identify full reptend primes

Created by: ChrisR

0

10

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

Created by: ChrisR

1

11

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

Created by: ChrisR

3

16

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

Created by: Ramon Villamangca

1

22

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

Created by: Richard Zapor

2

12

#### Problem 54700. Leyland Primes

Created by: Dyuman Joshi

1

5

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

Created by: elias GR

Tags primes, factors

4

408

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

Created by: Ramon Villamangca

1

5

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

Created by: ChrisR

4

11

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

Created by: ChrisR

0

6

#### Problem 42914. Counting the Grand Primes

Created by: John D'Errico

3

38

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

Created by: ChrisR

1

8

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

Created by: ChrisR

1

7

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

Created by: ChrisR

3

12

#### Problem 48075. Play PRIMEGAME

Created by: ChrisR

2

8

#### Problem 51758. List Proth primes

Created by: ChrisR

Tags primes

1

9

#### Problem 47895. List the dihedral primes

Created by: ChrisR

2

9

#### Problem 49783. List the good primes

Created by: ChrisR

Tags primes

1

11

#### Problem 60. The Goldbach Conjecture

Created by: Cody Team

Tags primes

56

4709

#### Problem 64. The Goldbach Conjecture, Part 2

Created by: Cody Team

Tags primes

16

1836

#### Problem 52183. List the nth prime quartet prefix

Created by: ChrisR

0

6

#### Problem 46066. Evaluate the logarithmic integral

Created by: ChrisR

1

12

#### Problem 46582. Find jumping medalists

Created by: ChrisR

3

13

#### Problem 46701. Compute the nth Naerogahtyp emirp

Created by: ChrisR

1

9

#### Problem 659. How long is the longest prime diagonal?

Created by: Ned Gulley

14

373

51 – 100 of 123