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Counting the Grand Primes
A grand prime pair is a pair of primes, p1 and p2=p1+1000, such that both numbers are prime. Like a twin prime pair, where the d...

11 months ago

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Euler–Mascheroni constant
Approximate the Euler-Mascheroni constant using the series representation gamma_n=\sum_{k=1}^{n} [1/k-ln(1+1/k)] Calculat...

11 months ago

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The sliding puzzle: 3D
This is an extension of problem 42842. In this case, the puzzle is three-dimensional and is of size 3x3x3. Of the 27 positions i...

11 months 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 ...

11 months 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...

11 months 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...

11 months ago

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Bouncy numbers
Inspired by Project Euler n°112. Working from left-to-right if no digit is exceeded by the digit to its left it is called an ...

11 months ago

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Determine if input is a valid AHP evaluation matrix
Input is a matrix. Output is a true or false statement (1 or 0). Return true if input is a valid Analytic Hierarchy Process eval...

11 months ago

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Outer product of multiple vectors
In tensor algebra, it is often useful to define a tensor as a product of lower order tensors. Similarly, a multidimensional arra...

11 months ago

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Combined Ages 3 - Non-symmetric, n ≥ 3
Pursuant to the previous two problems ( <http://www.mathworks.com/matlabcentral/cody/problems/42382-combined-ages-1-symmetric-n-...

11 months ago

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Combined Ages 4 - Non-symmetric with multiples, n ≥ 3
This problem is slightly more difficult than <http://www.mathworks.com/matlabcentral/cody/problems/42383-combined-ages-3-non-sym...

11 months ago

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Combined Ages 2 - Symmetric, n ≥ 3
Following on <http://www.mathworks.com/matlabcentral/cody/problems/42382-combined-ages-1-symmetric-n-3 Combined Ages 2>, you wil...

11 months ago

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It's going down. We're finding simbers!
This problem is inspired by Project Euler 520: Simbers. "We define a simber to be a positive integer in which any odd digit, ...

11 months ago

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Day counter function
Write a function called day_counter that returns the number of Mondays that fell on the first day of the month in a given year b...

11 months ago

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Pseudo Square Root (Inspired by Project Euler 266)
Shamelessly copied from the Project Euler page for Problem 266: ------------- The divisors of 12 are: 1,2,3,4,6 and 12. T...

11 months ago

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linear least squares fitting
Inputs: * |f|: cell-array of function handles * |x|: column vector of |x| values * |y|: column vector of |y| values, same l...

11 months ago

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Projector Matrix
Write a function to determine whether or not the matrix is a projector. Projector matrices are defined as P^2 = P.

11 months ago

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Pandigital Factors (Based on Euler 491)
A Pandigital Number is a number containing all of the digits from 0-9 inclusive, with the added stipulation that it does not hav...

11 months ago

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Pandigital Multiples of 11 (based on Project Euler 491)
A "Pandigital number of order X" is one that contains all of the numbers from 0 to X, but with no leading zeroes. If X>9, the cy...

11 months ago

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Project Euler 249: Prime Subset Sums
Inspired by Problem 249 of Project Euler. <https://projecteuler.net/problem=249> Let S = {2, 3, 5, ...} be the set of prime ...

11 months ago

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Decrypt the cypher using XOR encryption (for beginners)
Inspired by Project Euler n°59 Each character on a computer is assigned a unique code and the preferred standard is ASCII (...

11 months ago

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High Precision Square Root (Inspired by Project Euler 80)
Given a positive integer n which is not a perfect square, write a MATLAB script that will calculate the square root of n truncat...

11 months ago

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Longest Collatz Sequence
Inspired by Projet Euler n°14. The Collatz iterative sequence (See Cody problem n° 2103 and 211) is defined for the set of po...

11 months ago

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Pandigital number n°3 (Inspired by Project Euler 32)
After Problem 2319 and 2320. An n-digit number is pandigital if it makes use of all the digits 1 to n exactly ONCE. For examp...

11 months ago

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Pandigital number n°2 (Inspired by Project Euler 32)
After Problem 2319. An n-digit number is pandigital if it makes use of all the digits 1 to n exactly ONCE. For example, the 5-...

11 months 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...

11 months ago

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Highly divisible triangular number (inspired by Project Euler 12)
Triangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are: 1, 3, 6, 10, ...

11 months 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 ...

11 months 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 ? ...

11 months ago

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Sum of big primes without primes
Inspired by Project Euler n°10 (I am quite obviously a fan). With problem n°250 by Doug, you can find some global methods to co...

11 months ago

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