I'm just this guy, you know

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Birthday cake

It's Cody's 5th birthday, and you've been tasked with putting the candles on the cake. Your goal is to maximize the distance bet...

7 jours ago

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Champernowne Constant

The <http://en.wikipedia.org/wiki/Champernowne_constant Champernowne constant> is a real number whose digits in decimal represen...

8 jours ago

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P-smooth numbers

This Challenge is to find <https://en.wikipedia.org/wiki/Smooth_number P-smooth number> partial sets given P and a max series va...

8 jours ago

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Fermat's Last Theorem - Fermat's conjecture

Fermat's Last Theorem (sometimes called Fermat's conjecture, especially in older texts) states that no three positive integers a...

8 jours ago

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Happy 2013...

Happy 2013, everyone! An interesting tidbit about 2013 is that it is the first year since 1987 to contain four different digits...

8 jours ago

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Largest Twin Primes

<http://en.wikipedia.org/wiki/Twin_prime Twin primes> are primes p1, p2 = p1 + 2 such that both p1 and p2 are prime numbers. Giv...

8 jours ago

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Lychrel Number Test (Inspired by Project Euler Problem 55)

The task for this problem is to create a function that takes a number _n_ and tests if it might be a Lychrel number. This is, re...

8 jours ago

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Determine if input is a perfect number

A <http://en.wikipedia.org/wiki/Perfect_number/ perfect number> occurs whent the sum of all divisors of a positive integer, exce...

8 jours ago

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Determine if input is a Narcissistic number

<http://en.wikipedia.org/wiki/Narcissistic_number Narcissistic number> is a number that is the sum of its own digits each raised...

8 jours ago

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Mersenne Primes

A Mersenne prime is a prime number of the form M = 2^p - 1, where p is another prime number. For example, 31 is a Mersenne prim...

8 jours ago

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Numbers with prime factors 2, 3 and 5.

Make a function which takes one positive integer n and returns a matrix with the numbers of the form (2^i)*(3^j)*(5^k) which are...

8 jours ago

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Recurring Cycle Length (Inspired by Project Euler Problem 26)

Preface: This problem is inspired by <http://projecteuler.net/problem=26 Project Euler Problem 26> and uses text from that quest...

8 jours ago

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Project Euler: Problem 9, Pythagorean numbers

A Pythagorean triplet is a set of three natural numbers, a b c, for which, a^2 + b^2 = c^2 For example, 3^2 + 4^2 =...

8 jours ago

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Better Index Number

Let's say you want to save many, many files and append these files with a certain sortable index number. As you probably know, y...

11 jours ago

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Smallest n, for n! to have m trailing zero digits

For given positive integer n, its factorial often has many trailing zeros, in other words many factors of 10s. In order for n! t...

11 jours ago

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Whole Number Un-Concatenator

Write a function that accepts an integer and an index digit and returns a vector containing two integers which are the leading a...

11 jours ago

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Whole Number Concatenator

Write a function that concatenates whole numbers. For example: numcat(111,222) should return 111222 numcat(1,2,3,4,5) s...

11 jours ago

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The number of trailing zero digit of a factorial

For given positive integer n, take factorial of that number. How many trailing zeros does it have? Example: factorial(11) = 3...

11 jours ago

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The last non-zero digit of a factorial

For given positive integer n, what is the last non-zero digit of n!? Example: factorial(11) = 39916800 Last non-zero d...

11 jours ago

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Permutation Via Multiplication

Given two numbers a and b, determine if the product ab is a permutation of the digits of a. For example, this is always true for...

11 jours ago

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Lunar Arithmetic (Multiplication)

<https://oeis.org/A087061 OEIS link for a description of lunar arithmetic> Simply take the larger digit when adding and take ...

11 jours ago

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Lunar Arithmetic (Addition)

<https://oeis.org/A087061 OEIS link for a description of lunar arithmetic> Simply take the larger digit. Example 1: ...

11 jours ago

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Muphry's Law of MATLAB

You're running some simple multiplication problems through MATLAB for error checking purposes, but nothing seems to come up with...

11 jours ago

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Expand 10^n to Powers of 4

Given an integer n, return the coefficients c = [c_n,c_n-1,...,c_0] Such that 10^n = c_n*4^(n) + c_n-1*4^(n-1...

11 jours ago

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Numbers on 7-segment

This is a 7-segment: _ |_| |_| It's a 3-by-3 char matrix.It has made by 3 characters: '_' , '|' and ' ' (space...

11 jours ago

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Convert from Base 10 to base 5

Convert the input number from base 10 into base 5: for example: if a(in base 10)= 5 then a(in base 5)= 10

11 jours ago

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Still more miles to go before I sleep

It's time for more odometer fun. Last problem, my car's odometer hit 56789. It's coming up on 111111 now, which (barring a maj...

13 jours ago

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Pattern Sum

Write a function which receives two single digit positive integers, (k and m) as parameters and calculates the total sum as: k...

13 jours ago

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(Linear) Recurrence Equations - Generalised Fibonacci-like sequences

This problem is inspired by problems <http://uk.mathworks.com/matlabcentral/cody/problems/2187-generalized-fibonacci 2187>, <htt...

14 jours ago

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Fibonacci Decomposition

Every positive integer has a unique decomposition into nonconsecutive Fibonacci numbers f1+f2+ ... Given a positive integer n, r...

14 jours ago