# Problems

101 – 142 of 142
 Problem Title Likes Solvers Difficulty

#### Problem 54755. List odd twin composites

Created by: ChrisR

1

3

#### Problem 48040. Find the Pattern 5

Created by: Doddy Kastanya

0

53

#### Problem 45343. How lucky r u ?

Created by: Asif Newaz

2

12

#### Problem 52881. List the cuban primes

Created by: ChrisR

1

7

Created by: goc3

1

73

#### Problem 52629. Count the ways to draw non-intersecting chords between points on a circle

Created by: ChrisR

0

4

#### Problem 54345. Fill a rectangle with 1x1 and 2x2 tiles

Created by: ChrisR

Tags tiles, sequence

1

5

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

Created by: ChrisR

0

6

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

Created by: ChrisR

0

5

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

Created by: ChrisR

0

6

#### Problem 45423. Bernoulli's Triangle

Created by: Asif Newaz

Tags easy, sequence

1

14

#### Problem 51950. Find the smallest integer m such that n divides m!

Created by: ChrisR

1

8

#### Problem 48075. Play PRIMEGAME

Created by: ChrisR

2

8

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

Created by: ChrisR

1

8

#### Problem 47073. Find the nth Fibbinary number

Created by: ChrisR

2

10

#### Problem 47895. List the dihedral primes

Created by: ChrisR

2

9

#### Problem 52522. Easy Sequences 4: Eliminate the Days of Confusion

Created by: Ramon Villamangca

2

13

#### Problem 2190. Order of things - 2

Created by: J-G van der Toorn

2

10

#### Problem 45473. Sub-sequence - 01

Created by: Asif Newaz

Tags sequence

0

5

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

Created by: ChrisR

2

7

#### Problem 54775. Flip the parity of digits in a decimal expansion

Created by: ChrisR

1

3

#### Problem 54780. Trap a knight

Created by: ChrisR

0

2

#### Problem 53990. Classify product/digit-sum sequences

Created by: ChrisR

2

6

#### Problem 54355. Compute a determinant

Created by: ChrisR

0

4

#### Problem 54620. List the Euclid numbers

Created by: ChrisR

0

5

#### Problem 54645. Determine whether the input is an anagram number

Created by: ChrisR

0

4

#### Problem 54660. Generate the Figure-Figure sequence

Created by: ChrisR

2

5

#### Problem 54680. Determine whether a number is practical

Created by: ChrisR

2

4

#### Problem 45272. Pseudo-vampire number

Created by: Asif Newaz

2

19

#### Problem 53810. List the Beatriz numbers

Created by: ChrisR

2

4

#### Problem 2672. Largest Geometric Series

Created by: rifat

3

56

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

Created by: Ramon Villamangca

1

5

#### Problem 52644. List modest numbers up to n

Created by: ChrisR

3

5

#### Problem 52664. List the Moran numbers

Created by: ChrisR

3

6

#### Problem 45474. Sub-sequence - 02

Created by: Asif Newaz

Tags sequence

0

4

#### Problem 45475. Sub-sequence - 03

Created by: Asif Newaz

Tags sequence

1

4

#### Problem 52659. Easy Sequences 15: Pythagorean Area with maximum Hypotenuse

Created by: Ramon Villamangca

1

4

#### Problem 1506. Maximum Intra-Vector Swaps

Created by: Richard Zapor

0

7

#### Problem 2191. Order of things - 3

Created by: J-G van der Toorn

0

1

#### Problem 2192. Order of things - 4

Created by: J-G van der Toorn

0

2

#### Problem 45321. Kolakoski Sequence

Created by: Asif Newaz

1

5

#### Problem 44784. Project Euler: Problem 14 Longest Collatz sequence(harder version)

Created by: Binbin Qi

1

3

101 – 142 of 142