Problems

1 – 45 of 45

Problem Title Likes Solvers Difficulty

Problem 45192. check whether a number is a pentatope number

Created by: Asif Newaz

Tags pentatope

Problem 1012. Determine if input is a perfect number

Created by: Binbin Qi

Tags mod sum, perfect

156

Problem 45191. generate nth pentatope number

Created by: Asif Newaz

Tags number, pentatope

Problem 2061. Narcissistic number ?

Created by: Jean-Marie Sainthillier

Tags narcissistic

259

Problem 44748. Amicable numbers

Created by: cdeliu

Tags number theory, divisors

Problem 45223. find nth even fibonacci number

Created by: Asif Newaz

Tags series, number, fibonacci

Problem 1407. Is it an Armstrong number?

Created by: Harish Maradana

Tags armstrong no

241

Problem 1008. Determine if input is a Narcissistic number

Created by: Binbin Qi

Tags mod floor

135

Problem 2056. Is this number Munchhausen Narcissistic?

Created by: Ted

Tags math, narcissistic number, munchhausen

146

Problem 45253. Pell numbers

Created by: Asif Newaz

Tags number, sequence, pell

Problem 45229. Bell Triangle

Created by: Asif Newaz

Tags number, matrix, Magic Numbers

Problem 896. Sophie Germain prime

Created by: Aurelien Queffurust

Tags prime, primes, sophie germain

393

Problem 44836. Iccanobif numbers 1

Created by: James

Tags fibonacci, iccanobif

Problem 2690. Armstrong Number

Created by: VIVEK RUHELA

Tags arithmetic, basic matlab

263

Problem 45250. Be happy

Created by: Asif Newaz

Tags number, happy

Problem 2733. Evil Number

Created by: Jan Orwat

Tags easy, number theory, oeis

216

Problem 156. Parasitic numbers

Created by: the cyclist

Tags parasitic

255

Problem 44385. Extra safe primes

Created by: Matthew Eicholtz

Tags prime numbers, cody5, safe prime

685

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

Created by: Jan Orwat

Tags number theory, a138591

129

Problem 1298. P-smooth numbers

Created by: Richard Zapor

Tags primes, find, mod

Problem 44360. Pentagonal Numbers

Created by: goc3

Tags series, number, sequence

597

Problem 45194. Cantor counting

Created by: Asif Newaz

Tags cantor, rational number

Problem 166. Kaprekar numbers

Created by: the cyclist

Tags kaprekar

243

Problem 1096. Largest Twin Primes

Created by: Des Mc Manus

Tags primes

332

Problem 933. Ordinal numbers

Created by: Tim

Tags ordinal, lookup table

131

Problem 1804. Fangs of a vampire number

Created by: Andrew Newell

Tags factors, number theory

Problem 165. Woodall number

Created by: the cyclist

Tags woodall number theory

139

Problem 1082. Lychrel Number Test (Inspired by Project Euler Problem 55)

Created by: @bmtran (Bryant Tran)

Tags projecteuler, plus15

Problem 525. Mersenne Primes

Created by: Drew Weymouth

Tags math, prime, integers

350

Problem 45249. Frugal number

Created by: Asif Newaz

Tags number, frugal, economical

Problem 2595. Polite numbers. Politeness.

Created by: Jan Orwat

Tags number theory, oeis

121

Problem 1190. Golomb's self-describing sequence (based on Euler 341)

Created by: James

Tags projecteuler, self-referential, golomb sequence

117

Problem 74. Balanced number

Created by: Cody Team

Tags matlab

2074

Problem 249. Project Euler: Problem 9, Pythagorean numbers

Created by: Doug Hull

Tags projecteuler

496

Problem 1742. Generate a Parasitic Number

Created by: James

Tags parasitic, cyclic

Problem 45251. Last non-zero digit

Created by: Asif Newaz

Tags number, factorial

Problem 1925. Smith numbers

Created by: Sky Sartorius

Tags sum, factors

349

Problem 1477. Champernowne Constant

Created by: G K

Tags math

Problem 45272. Pseudo-vampire number

Created by: Asif Newaz

Tags numbers, number theory, sequence

Problem 1825. Find all vampire fangs

Created by: Andrew Newell

Tags factors, number theory

Problem 235. Project Euler: Problem 4, Palindromic numbers

Created by: Doug Hull

Tags projecteuler

444

Problem 81. Mandelbrot Numbers

Created by: Cody Team

Tags matlab, fractals

823

Problem 1095. Circular Primes (based on Project Euler, problem 35)

Created by: James

Tags primes, projecteuler, circular reasoning

251

Problem 1826. Find vampire numbers

Created by: Andrew Newell

Tags factors, number theory

248

Problem 45274. Fangs of pseudo-vampire number

Created by: Asif Newaz

Tags number theory, vampire

1 – 45 of 45

Trial software

Difficulty Rating

Problem Groups

Problems