ROBERTO

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Divisible by n, prime divisors - 11, 13, 17, & 19
Divisibility checks against prime numbers can all be accomplished with the same routine, applied recursively, consisting of add ...

12 hours 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...

12 hours ago

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Is it an Armstrong number?
An Armstrong number of three digits is an integer such that the sum of the cubes of its digits is equal to the number itself. Fo...

13 hours 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...

13 hours 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...

13 hours ago

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Negative without '-'
Simple: return a negative number without using the '-' sign. Thanks to Problem <https://www.mathworks.com/matlabcentral/cody/...

1 day ago

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Pseudo-vampire number
refer to <https://en.wikipedia.org/wiki/Vampire_number> Given a number x, determine whether it is a pseudo-vampire number. A p...

1 day ago

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Divisible by n, prime divisors from 20 to 200
Pursuant to the previous problem (linked below), this problem requires a function that checks for divisibility of large numbers ...

2 days ago

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Divisors for big integer
Inspired by Problem 1025 and Project Euler 12. Given n, return the number y of integers that divide N. For example, with ...

3 days ago

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Divisible by 6
Pursuant to the <http://www.mathworks.com/matlabcentral/cody/problems/42404-divisible-by-2 first problem> in this series, this o...

3 days ago

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Project Euler: Problem 5, Smallest multiple
2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder. What is the smalle...

3 days ago

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Project Euler: Problem 1, Multiples of 3 and 5
If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23...

3 days ago

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Project Euler: Problem 11, Largest product in a grid
What is the greatest product of k adjacent numbers in the same direction (up, down, left, right, or diagonally) in a n×n grid ? ...

3 days ago

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Hexagonal numbers on a spiral matrix
Put hexagonal numbers in a ( m x m ) spiral matrix and return the sum of its diagonal elements. Formula of hexagonal numbers ...

3 days ago

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Infinite precision division
Develop a function that will divide a very very large integer numerator, supplied to function as a string (e.g., '12233344445555...

3 days ago

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Sums of cubes and squares of sums
Given the positive integers 1:n, can you: 1. Compute twice the sum of the cubes of those numbers. 2. Subtract the square...

4 days ago

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Project Euler: Problem 16, Sums of Digits of Powers of Two
2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26. What is the sum of the digits of the number 2^N? Thanks ...

4 days ago

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Large Sum (inspired by Project Euler 13)
Your function will be provided an arbitrary number of numbers of arbitrary sizes as a cell array of strings. Some numbers will b...

4 days ago

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Divisible by 13
Write a function to determine if a number is divisible by 13. Similar to the number seven, this can be done by a few different m...

5 days ago

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Recaman Sequence - I
Recaman Sequence (A005132 - <http://oeis.org/A005132 - OEIS Link>) is defined as follow; seq(0) = 0; for n > 0, seq(n) ...

5 days ago

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Sums of Multiple Pairs of Triangular Numbers
This is a follow-up to <https://www.mathworks.com/matlabcentral/cody/problems/44289 Problem 44289> - Find two triangular numbers...

5 days ago

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Find two triangular numbers whose sum is input.
Find two triangular numbers whose sum is _input_. Note: The difference beetween the triangular numbers should be minimum.

5 days ago

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Write c^3 as sum of two squares a^2+b^2
write c^3 as sum of two squares a^2+b^2. a and b must be integer and greater than zero. For example 5^3 = 2^2 + 11^2 5...

5 days ago

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Matlab Basics - y as a function of x
Write a function to calculate y as a function of x, such that y = 6x^2 + 5x - 2

5 days ago

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How to multiply?
Imagine you are in 3012 Anno Domini, when everyone must learn how to multiply, and competing for the highly prestigious post of...

5 days ago

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Convert a vector into a number
This is a sub problem related to this problem: <http://www.mathworks.com/matlabcentral/cody/problems/621-cryptomath-addition>...

6 days ago

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Coin Distribution - 02
Prev prob <https://www.mathworks.com/matlabcentral/cody/problems/45385-coin-distribution> Given a set of coins and an amount,...

6 days ago

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Inscribed Pentagon?
Your function will be provided with the five vertices of a pentagon (p) as well as the center point (cp) and radius (r) of a cir...

10 days ago

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Draw 'F'
Draw a x-by-x matrix 'F' using 1 and 0. (x is odd and bigger than 4) Example: x=5 ans= [1 1 1 1 1 1 0 0 0 0 ...

10 days ago

Solved

Draw 'E'
Draw a x-by-x matrix 'E' using 1 and 0. (x is odd and bigger than 4) Example: x=5 ans= [1 1 1 1 1 1 0 0 0 0 ...

10 days ago