Cody

# Problems

51 – 100 of 111
 Problem Title Likes Solvers Difficulty

#### Problem 656. Calculate Euler's phi function

Created by: Freddy

1

78

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

Created by: Ramon Villamangca

1

7

#### Problem 45342. Sieve of Eratosthenes

Created by: Asif Newaz

2

13

#### Problem 2734. N-th Odious

Created by: Jan Orwat

3

145

#### Problem 51715. Iterate the sum of divisors and totient

Created by: ChrisR

2

6

#### Problem 52085. Compute a sum involving the totient over divisors of a number

Created by: ChrisR

0

5

#### Problem 46003. Compute Khinchin's constant

Created by: ChrisR

2

11

#### Problem 49788. Carmichael Number

Created by: Gifari Zulkarnaen

3

9

#### Problem 46099. Identify full reptend primes

Created by: ChrisR

0

9

#### Problem 2797. modular arithmetic

Created by: rifat

2

37

#### Problem 2735. Binary Neighbourhood

Created by: Jan Orwat

2

57

#### Problem 2595. Polite numbers. Politeness.

Created by: Jan Orwat

6

122

#### Problem 49582. Determine whether a square can be drawn on a grid of dots

Created by: ChrisR

4

7

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

Created by: ChrisR

2

10

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

Created by: ChrisR

0

7

#### Problem 46582. Find jumping medalists

Created by: ChrisR

3

12

#### Problem 52609. Easy Sequences 11: Factorial Digits without Trailing Zeros

Created by: Ramon Villamangca

0

4

#### Problem 52614. Easy Sequences 12: 50th Prime

Created by: Ramon Villamangca

0

3

#### Problem 52634. Easy Sequences 14: Consecutive Composites

Created by: Ramon Villamangca

0

1

#### Problem 52679. Easy Sequences 16: Volume of Embedded Octahedron

Created by: Ramon Villamangca

1

4

#### Problem 52729. Easy Sequences 21: Combinatorial Summations

Created by: Ramon Villamangca

2

2

#### Problem 52764. Easy Sequences 24: Number of Coprime Lattice Points

Created by: Ramon Villamangca

0

2

#### Problem 52809. Easy Sequences 28: Sum of Radicals of Integers

Created by: Ramon Villamangca

1

3

#### Problem 52814. Easy Sequences 27: Product of Radicals of Integers

Created by: Ramon Villamangca

1

3

#### Problem 52819. Easy Sequences 30: Nearly Pythagorean Triangles

Created by: Ramon Villamangca

2

3

#### Problem 52849. Easy Sequences 34: Modified Pascal's Triangle

Created by: Ramon Villamangca

0

2

#### Problem 53109. Easy Sequences 52: Non-squarable Rectangles

Created by: Ramon Villamangca

1

1

#### Problem 53119. Easy Sequences 53: Greatest Proper Divisor

Created by: Ramon Villamangca

1

1

#### Problem 45272. Pseudo-vampire number

Created by: Asif Newaz

2

18

#### Problem 51077. List composite numbers that cannot be written as the sum of two primes

Created by: ChrisR

2

7

#### Problem 51565. Convert a number from base 10 to factorial notation

Created by: ChrisR

2

5

#### Problem 2848. Digital Neighbourhood

Created by: Jan Orwat

2

49

#### Problem 42834. Integer complexity (Large numbers)

Created by: Peng Liu

1

11

#### Problem 42889. Should Mr McNugget even get out of bed today?

Created by: James

1

11

#### Problem 45831. Compute the Bernoulli numbers

Created by: ChrisR

0

8

#### Problem 45939. Estimate π from certain values of the zeta function

Created by: ChrisR

0

6

#### Problem 46066. Evaluate the logarithmic integral

Created by: ChrisR

1

12

#### Problem 1825. Find all vampire fangs

Created by: Andrew Newell

2

50

#### Problem 45997. Evaluate the zeta function for complex arguments

Created by: ChrisR

0

8

#### Problem 1826. Find vampire numbers

Created by: Andrew Newell

9

249

#### Problem 52724. Easy Sequences 20: Counting Prime-sided Rectangles

Created by: Ramon Villamangca

Tags easy, geometry, area

1

3

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

Created by: Ramon Villamangca

0

3

#### Problem 52978. Easy Sequences 44: Finding the Smallest Number whose Cube is divisible by a Factorial

Created by: Ramon Villamangca

0

3

#### Problem 45274. Fangs of pseudo-vampire number

Created by: Asif Newaz

1

15

#### Problem 52769. Easy Sequences 22: Sum of Proper Fractions

Created by: Ramon Villamangca

1

4

#### Problem 52804. Easy Sequences 29: Odd proper divisors of odd proper divisors

Created by: Ramon Villamangca

1

2

#### Problem 52861. Easy Sequences 37: Natural Factorable Polynomials

Created by: Ramon Villamangca

0

2

#### Problem 53079. Easy Sequences 50: Blocked Gaussian Integers

Created by: Ramon Villamangca

0

2

#### Problem 52709. Easy Sequences 19: Length of Prime-sided Rectangle with Maximum Area

Created by: Ramon Villamangca

Tags easy, geometry, area

1

3

#### Problem 52866. Easy Sequences 36: Hyperbolic Lattice Points

Created by: Ramon Villamangca

0

3

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