Problems

101 – 150 of 167

Problem Title Likes Solvers Difficulty

Problem 53990. Classify product/digit-sum sequences

Created by: ChrisR

Tags number theory, sequence, noeis

Problem 54740. Count the ways to make Scorigami

Created by: ChrisR

Tags number theory, sports, coin problems

Problem 55335. Generate Bernoulli polynomials

Created by: ChrisR

Tags number theory, integral, ordinary differential equation

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

Created by: ChrisR

Tags number theory, factorial, expansion

Problem 56220. Easy Sequences 75: Easy as Pisano Pi

Created by: Ramon Villamangca

Tags easy, sequences, fibonacci

Problem 56250. Counting Permutations

Created by: Dyuman Joshi

Tags permutations, numbers, number theory

Problem 56418. Easy Sequences 78: Trailing Zeros of Factorial Numbers at any Base

Created by: Ramon Villamangca

Tags easy, number theory, simple

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

Created by: ChrisR

Tags primes, number theory, sequence

Problem 52866. Easy Sequences 36: Hyperbolic Lattice Points

Created by: Ramon Villamangca

Tags easy, number theory, simple

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

Created by: Ramon Villamangca

Tags easy, geometry, area

Problem 53810. List the Beatriz numbers

Created by: ChrisR

Tags primes, number theory, sequence

Problem 56423. French Conundrum

Created by: Dyuman Joshi

Tags numbers, number theory

Problem 45272. Pseudo-vampire number

Created by: Asif Newaz

Tags numbers, number theory, sequence

Problem 54720. Hyperperfect Numbers

Created by: Dyuman Joshi

Tags numbers, number theory

Problem 55370. Easy Sequences 69: Radix Economy of Factorials

Created by: Ramon Villamangca

Tags easy, basics, number theory

Problem 1826. Find vampire numbers

Created by: Andrew Newell

Tags factors, number theory

282

Problem 45997. Evaluate the zeta function for complex arguments

Created by: ChrisR

Tags number theory, zeta function, special functions

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

Created by: Ramon Villamangca

Tags easy, geometry, number theory

Problem 53119. Easy Sequences 53: Greatest Proper Divisor

Created by: Ramon Villamangca

Tags easy, number theory, simple

Problem 56433. Canadian Conundrum

Created by: Dyuman Joshi

Tags numbers, number theory

Problem 52819. Easy Sequences 30: Nearly Pythagorean Triangles

Created by: Ramon Villamangca

Tags easy, geometry, number theory

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

Created by: Ramon Villamangca

Tags easy, geometry, area

Problem 52614. Easy Sequences 12: 50th Prime

Created by: Ramon Villamangca

Tags easy, sequences, primes

Problem 52634. Easy Sequences 14: Consecutive Composites

Created by: Ramon Villamangca

Tags easy, sequences, number theory

Problem 52990. Easy Sequences 46: Semi-prime Leap Year Pairs

Created by: Ramon Villamangca

Tags easy, number theory, simple

Problem 53009. Easy Sequences 48: Prime Big Omega of Factorial Sequence

Created by: Ramon Villamangca

Tags easy, primes, number theory

Problem 53079. Easy Sequences 50: Blocked Gaussian Integers

Created by: Ramon Villamangca

Tags easy, number theory, simple

Problem 53955. Determine Fundamental Solution of Pell Equation

Created by: David Hill

Tags number theory, pell

Problem 51580. Construct a continued fraction for a square root

Created by: ChrisR

Tags number theory, continued fractions, u. surrey

Problem 56458. Easy Sequences 80: Sum of the n-th Row of Fibonacci Square Triangle

Created by: Ramon Villamangca

Tags easy, fibonacci, number theory

Problem 42834. Integer complexity (Large numbers)

Created by: Peng Liu

Tags integer, number theory, complexity

Problem 45274. Fangs of pseudo-vampire number

Created by: Asif Newaz

Tags number theory, vampire

Problem 52769. Easy Sequences 22: Sum of Proper Fractions

Created by: Ramon Villamangca

Tags easy, number theory, sequence

Problem 52729. Easy Sequences 21: Combinatorial Summations

Created by: Ramon Villamangca

Tags easy, combinatorics, number theory

Problem 52859. Easy Sequences 35: Cutting a donut to Semi-prime pieces

Created by: Ramon Villamangca

Tags easy, number theory, simple

Problem 52861. Easy Sequences 37: Natural Factorable Polynomials

Created by: Ramon Villamangca

Tags easy, algebra, number theory

Problem 54800. Consecutive Pairs of Smooth Numbers from Set of Prime Numbers

Created by: David Hill

Tags number theory, smooth number

Problem 56553. Easy Sequences 81: Fibonacci Radicals

Created by: Ramon Villamangca

Tags easy, fibonacci, number theory

Problem 57487. Compute the largest number with a given integer complexity

Created by: ChrisR

Tags number theory, sequence

Problem 52684. Easy Sequences 17: Mu Variant Function

Created by: Ramon Villamangca

Tags easy, sequences, function

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

Created by: Ramon Villamangca

Tags easy, geometry, number theory

Problem 2160. The 17x17 Problem

Created by: Ned Gulley

Tags 17x17, number theory

Problem 44788. Find the right number make the equation

Created by: Binbin Qi

Tags number theory, positive number, Diophantine equations

Problem 52834. Easy Sequences 32: Almost Pythagorean Triples

Created by: Ramon Villamangca

Tags easy, geometry, number theory

Problem 53125. Easy Sequences 54: Product of Products of Proper Divisors

Created by: Ramon Villamangca

Tags easy, number theory, simple

Problem 53730. Easy Sequences 57: "Pretty-gorean" Triangles?

Created by: Ramon Villamangca

Tags easy, geometry, number theory

Problem 53740. Easy Sequences 59: Almost Twin Primes

Created by: Ramon Villamangca

Tags easy, primes, number theory

101 – 150 of 167

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