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Easy Sequences 42: Areas of Non-constructible Polygons
A constructible polygon is a regular polygon that can be constructed using only a compass and a straightedge. Amazingly, Gauss ...

1 year ago

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Easy Sequences 41: Boxes with Integer Edges
For this problem, we are asked to write a function that will count the number of boxes with integer edges, that has the same giv...

1 year ago

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Easy Sequences 39: Perfect Squares in Pascal's Triangle
Consider the 2nd, 3rd and 4th diagonals of the Pascal's Triangle, shown highlighted below: ...

1 year ago

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Easy Sequences 38: Prime Number Delta
The Prime Number Theorem states that: where is the prime counting function (number of pri...

1 year ago

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Sum the elements in rows of the Levine triangle
The Levine triangle starts as follows: Row 0: 2 Row 1: 1 1 Row 2: 1 2 Row 3: 1 1 2 To construct each row, r...

1 year ago

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Fill a rectangle with 1x1 and 2x2 tiles
A 3x2 rectangle can be filled with 1x1 and 2x2 tiles in three ways: The colors merely distinguish the sizes of the tiles. A 3...

1 year ago

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Count the ways to draw non-intersecting chords between points on a circle
There are 9 ways to draw non-intersecting chords between four points on the perimeter of a circle (including no chords at all). ...

1 year ago

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Count unique orderings of vertices of a polygon
Cody Problem 2671 asks us to determine whether four points can be the corners of a rectangle. The points are not necessarily inp...

1 year ago

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Classify product/digit-sum sequences
Cody Problem 53120 involved a sequence in which a term is computed by multiplying the previous two terms and adding the digits o...

1 year ago

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Compute the Sequence of the Day
A sequence starts with 1 and 2, and each subsequent term is the sum of the digits of the product of the previous two terms. As a...

1 year ago

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List the dopey numbers
If vile numbers have binary representations that end with an even number of zeros (even vile), then numbers with binary represe...

1 year ago

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List the vile numbers
Evil numbers, the subject of Cody Problem 2733 have an even number of ones in their binary representations, whereas odious numbe...

1 year ago

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List modest numbers up to n
After determining the nude numbers, or the numbers that openly display some of their divisors as their digits, one would think t...

1 year ago

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Determine whether a number is a fibodiv number
The number 14 is a fibodiv number because you can divide it into 1 and 4, use those numbers as the seeds for a Fibonacci sequenc...

1 year ago

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Find the nth nude number
The number 672 is a nude number because it openly displays three of its divisors: 6, 7, and 2. In other words, a nude number is ...

1 year ago

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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...

1 year 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 ...

1 year ago

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Iterate the sum of divisors and totient

1 year ago

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Solve a nonlinear difference equation

1 year 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...

1 year 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...

1 year 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...

1 year 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....

1 year 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...

1 year 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...

1 year 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(...

1 year 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.

1 year 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 ...

1 year 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: ...

1 year 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...

1 year ago