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List the Moran numbers
The quotient of a Moran number and its digit sum is prime. For example, 117 and 481 are Moran numbers because 117/(1+1+7) is 13 ...

30 days ago

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Evaluate the logarithmic integral
The <https://en.wikipedia.org/wiki/Logarithmic_integral_function logarithmic integral> li(x) plays a role in number theory becau...

1 month ago

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Construct the number counts sequence
A sequence is constructed in the following way. The zeroth term is 1, and the next terms are determined by counting the number i...

1 month ago

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Calculate y=2
Find the value of x so that y=2

1 month ago

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List the first of three consecutive square-free numbers
The numbers 13, 14, and 15 are consecutive, of course, but they also share the property of being square-free. That is, each numb...

1 month ago

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Get ranking of a combination
I have the numbers pulled without replacement from the set [1 2 3 4 5 6 7 8 9 10 11 12 13]; They are then ordered from least to ...

2 months ago

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Count the primes resulting from changing one digit of a number
If you start with the number 24 and seek primes by changing a single digit, you can find two: 23 and 29. If you start with 130, ...

2 months ago

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Solve an easy binary puzzle
A binary puzzle presents a square grid (or matrix) of cells in which each cell must be 0 or 1. The finished puzzle must follow t...

2 months ago

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Boolean algebra
Your contractor from Elbonia has sent you the prototype of the new logical unit. It turns out that the only logical relation it ...

2 months ago

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Convert integers from base 10 to proper primary notation
This problem is the companion to Cody Problem 60782. The proper primary system of expressing numbers has three digits: m, x, and...

2 months ago

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Convert integers from proper primary to base 10
The proper primary system of expressing numbers has three digits: m, x, and p, which correspond to -1, 0, and 1. The places in a...

2 months ago

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Express integers in negabinary
Negabinary numbers are written in base -2. For example, the negabinary number 11010 is , or 6 in base 10. In a similar way, -3 i...

2 months ago

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Play Hocus Focus
The card game Hocus Focus starts by placing twelve cards with wizards face up on a table. The characteristics of the wizards tha...

2 months ago

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Complete hydraulic geometry relations
Hydraulic geometry relations express the velocity , width , and depth of a river as a function of the discharge (or flow) , whi...

3 months ago

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Simple addition
Add two numbers using a funciton

3 months ago

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EZ10
EZ

3 months ago

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EZ9
EZ

3 months ago

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EZ8
EZ

3 months ago

Solved

EZ7
EZ

3 months ago

Solved

Times 2 - START HERE
Try out this test problem first. Given the variable x as your input, multiply it by two and put the result in y. Examples:...

3 months ago

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Divisible by n, Composite Divisors
Pursuant to <http://www.mathworks.com/matlabcentral/cody/problems/42453-divisible-by-n-prime-vs-composite-divisors Divisible by ...

3 months ago

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Divisible by n, Truncated-number Divisors
Some divisors only require a few numbers at the end of the number in question to determine divisibility, no matter how long. Exa...

3 months 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 ...

3 months ago

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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 ...

3 months ago

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EZ
EZ

3 months ago

Solved

EZZ
EZZ

3 months ago

Solved

EZ4

3 months ago

Solved

EZ5
EZ5

3 months ago

Solved

EZ6

3 months ago

Solved

Identify points inside a Reuleaux triangle
Write a function to identify points that lie in or on a Realeaux triangle, which is a curve of constant width. The input to the ...

3 months ago