Problems

1 – 50 of 140

Problem Title Likes Solvers Difficulty

Problem 2738. Sideways sum

Created by: Jan Orwat

Tags easy, number theory, pop series

Problem 45189. Double Factorial

Created by: Mehmet OZC

Tags number theory, factorial, double factorial

Problem 46305. find the value

Created by: Maryam HCTRAK Alhebsi

Tags number theory

Problem 46000. Compute the harmonic numbers

Created by: ChrisR

Tags number theory

Problem 47803. Check if the input is a strong prime

Created by: Mehmet OZC

Tags primes, number theory, strong prime

Problem 46054. Count trailing zeros in a primorial

Created by: ChrisR

Tags primes, number theory, primorial

Problem 54370. Determine whether the given number is palindrome or not.

Created by: Abdullah Al Baki

Tags basic matlab, string manipulation, number theory

Problem 43130. Nth root

Created by: Abhishek Jain

Tags numbers, root, number theory

Problem 49738. Determine whether a prime is Pythagorean

Created by: ChrisR

Tags primes, pythagoras, number theory

Problem 52060. Identify Ruth-Aaron numbers

Created by: ChrisR

Tags number theory, baseball, factor sum

Problem 46639. Transform a Decimal number into a Septimal number

Created by: Syed Shahed

Tags numbers, number theory

Problem 42865. Find the sum of n squares

Created by: William Mitchell

Tags number theory

163

Problem 43082. Reverse digits of a number

Created by: Mohammad Haghighat

Tags math, numbers, basic matlab

Problem 2369. Tribute to Ramanujan

Created by: rifat

Tags number theory

Problem 52921. Easy Sequences 40: Quadratic Congruence

Created by: Ramon Villamangca

Tags easy, number theory, simple

Problem 45224. Wythoff Sequence

Created by: Asif Newaz

Tags number theory, sequence, oeis

Problem 44748. Amicable numbers

Created by: cdeliu

Tags number theory, divisors

Problem 51570. Count numbers whose reciprocals' decimal expansions terminate

Created by: ChrisR

Tags decimals, number theory

Problem 2370. Fermat's last theorem - again

Created by: rifat

Tags number theory

Problem 45960. Set the Euler-Mascheroni constant with an identity using available MATLAB functions

Created by: ChrisR

Tags numbers, number theory

Problem 47798. Check if the input is a balanced prime

Created by: Mehmet OZC

Tags primes, number theory, balanced prime

Problem 51798. Label primes with the Erdos-Selfridge classification

Created by: ChrisR

Tags primes, number theory, guy a18

Problem 45388. Gapful numbers

Created by: Asif Newaz

Tags numbers, number theory, time complexity

Problem 46016. Determine digits of the Copeland-Erdos constant

Created by: ChrisR

Tags numbers, number theory

Problem 47808. Check if the input is an interprime

Created by: Mehmet OZC

Tags primes, number theory, interprime

Problem 1927. Find nth maximum

Created by: Awadhesh Srivastava

Tags number theory, n th max

576

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

Created by: ChrisR

Tags primes, number theory, primorial

Problem 44230. I'm going to enjoy watching you calculate, Mr Anderson

Created by: James

Tags number theory, phone numbers, agent smith

Problem 50182. Compute the Euler totient function

Created by: ChrisR

Tags primes, number theory

Problem 46046. Determine whether a number is a cluster prime

Created by: ChrisR

Tags primes, number theory

Problem 44229. How brilliant are you?

Created by: James

Tags factors, number theory, brilliant

Problem 43179. Red and green towers

Created by: Giovanni Mottola

Tags arithmetic, number theory

Problem 45988. Evaluate the zeta function for real arguments > 1

Created by: ChrisR

Tags number theory, zeta function, special functions

Problem 1771. Polygonal numbers

Created by: Jan Orwat

Tags number theory, sequence, polygonal

115

Problem 44289. Find two triangular numbers whose sum is input.

Created by: Mehmet OZC

Tags number theory, triangular numbers

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

Created by: ChrisR

Tags primes, number theory, sequence

Problem 52594. Easy Sequences 10: Sum of Cumsums of Fibonacci Sequence

Created by: Ramon Villamangca

Tags easy, sequences, fibonacci

Problem 2733. Evil Number

Created by: Jan Orwat

Tags easy, number theory, oeis

227

Problem 46060. Identify primorial primes

Created by: ChrisR

Tags primes, number theory, primorial

Problem 44068. The number of trailing zero digit of a factorial

Created by: Jihye Sofia Seo

Tags integer, number theory, factorial

Problem 2593. Polite numbers. N-th polite number.

Created by: Jan Orwat

Tags number theory, a138591

142

Problem 45342. Sieve of Eratosthenes

Created by: Asif Newaz

Tags prime, numbers, number theory

Problem 45424. Amicable pair

Created by: Asif Newaz

Tags number theory

Problem 45964. Compute the nth Pythagorean prime

Created by: ChrisR

Tags primes, pythagoras, number theory

Problem 46081. Set Soldner's constant

Created by: ChrisR

Tags number theory, special functions

Problem 53880. List the vile numbers

Created by: ChrisR

Tags binary, number theory, anagrams

Problem 44319. Write c^3 as sum of two squares a^2+b^2

Created by: Mehmet OZC

Tags number theory, cody5

302

Problem 1804. Fangs of a vampire number

Created by: Andrew Newell

Tags factors, number theory

Problem 44065. Number of even divisors of a given number

Created by: Jihye Sofia Seo

Tags factor, integer, number theory

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

Created by: ChrisR

Tags geometry, pythagoras, factor

1 – 50 of 140

Difficulty Rating

Problem Groups

Problems