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Find numbers in the Popular Computing Z-sequence
Here’s a quick one. In 1977 the magazine Popular Computing sought “problem situations for which the computer is the best (if not...

3 years ago

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Identify Ruth-Aaron numbers
After Hank Aaron hit his 715th home run and passed Babe Ruth’s total of 714, Carl Pomerance noticed that the union of the prime ...

3 years ago

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Iterate the sum of divisors and totient

3 years ago

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Solve a nonlinear difference equation

3 years ago

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Find the smallest integer m such that n divides m!
Write a function that takes an integer and finds the smallest integer whose factorial is divisible by . For example, if , then...

3 years ago

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Does matlab have any function that can compare multiple numbers and return logical value zero or one?
With a vector of singles or doubles, you could use ~std([a b c d]). If all the values are the same, the standard deviation will...

3 years ago | 0

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Amicable numbers
Test whether two numbers are <https://en.wikipedia.org/wiki/Amicable_numbers amicable>, meaning that the sum of the proper divis...

3 years ago

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Approximate e
Given a and n, compute and approximation to f = a * e ^ n, without the use of exp, string operations, or floating point numbers....

3 years ago

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How many unique Pythagorean triples?
For a given integer |n|, return all <https://en.wikipedia.org/wiki/Pythagorean_triple Pythagorean triples> that inlude numbers s...

3 years ago

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Goldbach's marginal conjecture - Write integer as sum of three primes
Goldbach's strong conjecture states that every even integer greater than 2 can be expressed as the sum of two primes. For exampl...

3 years ago

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Consecutive Powers
Return 2 numbers and 2 powers such that their difference is 1 A 4 element row vector is expected: x where x(1)^x(2) - x(...

3 years 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.

3 years ago

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I'm going to enjoy watching you calculate, Mr Anderson
Smith numbers are numbers such that if you add up all of the digits in the number, that sum equals the sum of all of the digits ...

3 years ago

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How brilliant are you?
A Brilliant number is defined as a number with two prime factors, both of which have the same number of digits. Some examples: ...

3 years ago

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calculate PI without using pi function
There are many methods to get the pi(Ratio of circumference to diameter). You should get pi without using the pi function in M...

3 years ago

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Polar Form Complex Number Entry
Write a function that takes the magnitude and angle(in degrees) of a complex number and returns a complex variable. Positive ang...

3 years ago

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Lah Numbers
Create a square lower diagonal matrix containing the first n Lah number coefficients. In mathematics, the Lah numbers are coeffi...

3 years ago

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Find Pseudo-Cyclic Number
A cyclic number is an integer in which cyclic permutations of the digits are successive multiples of the number https://en.wikip...

3 years ago

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Nth roots of unity
First, find the n nth roots of unity. eg if n = 6, find the n distinct (complex) numbers such that n^6 = 1. <https://en.wiki...

3 years ago

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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...

3 years 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...

3 years ago

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Hilbert numbers
Given a positive integer, n, return h as follows: 1. If n is not a <https://en.wikipedia.org/wiki/Hilbert_number Hilbert numb...

3 years 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...

3 years 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, ...

3 years 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 ...

3 years ago

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Easy Sequences 81: Fibonacci Radicals
The radical of a positive integer is defined as the product of the distinct prime numbers dividing . For example, the distinct ...

3 years ago

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Sphenic number sequence
Sphenic numbers are positive integers that are products of three distinct prime numbers: 30, 42, 66, 70, 78, 102, 105, 110, 114,...

3 years ago

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Easy Sequences 80: Sum of the n-th Row of Fibonacci Square Triangle
We shall call the following arrangement of Fibonacci numbers, as the Fibonacci Square Triangle: where...

3 years ago

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Easy Sequences 79: Trailing Zeros of Fibonorial Numbers at any Base
The fibonorial of an integer is defined as follows: where: is the -th Fibonacci number ( and for ). I...

3 years ago

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Easy Sequences 76: Not so easy as Pisano Pi
Pisano period , of an integer , is the period in which the sequence of Fibonacci numbers modulo repeats. For example it is not ...

3 years ago