# Questions tagged [math]

The challenge involves mathematics in some central way. Also consider using more specific tags, listed in the tag wiki info.

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### In between fractions

Given two positive integer fractions $x$ and $y$ such that $x < y$, give the fraction $z$ with the smallest positive integer denominator such that it is between $x$ and $y$. For example ...
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### Find the Lowest Allowable Integer Which is an Optimal Even-Harmonic of the Values in a List [closed]

PROBLEM For a list of numbers, list: Find the lowest possible integer, x, which is optimally close to the whole number even-...
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### Alternating sums of multidimensional arrays

Given a multidimensional array, find the recursive alternating sum. An alternating sum is simply the sum of an array, where every other item (starting with the second) is negated. For example, the ...
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### ASCII-Art n'th Root

Challenge: Given two integers $a$ and $b$, with lengths $A=length(a), B=length(b)$, output an ASCII-art of the $a^{th}$ root of $b$, including the answer rounded to $A$ amount of decimal ...
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1 vote
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### Egyptian fraction representations of 1

An Egyptian fraction is a representation of a rational number using the sum of distinct unit fractions (a unit fraction is of the form $\frac 1 x$ where $x$ is a positive integer). For all[1] ...
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### Output every sublist ... eventually

You will be given as input an infinite stream of positive integers. Your task is to write a program which outputs an infinite sequence of lists with two requirements: All lists in the output are ...
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763 views

### Generate Fmbalbuena Numbers

My user id is 106959 How to check if the number is Fmbalbuena number? First Step: Check if the number of digits is a multiple of 3: ...
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150 views

### Indices of square numbers that are also pentagonal [closed]

First 15 numbers of the A046173: ...
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### Total cost of The 12 Days of Christmas

Introduction I have decided that this Christmas, as a "present" to a friend, I wish to purchase the things described in the classic song "The 12 Days of Christmas". The only ...
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### How to shorten the Python code? Part II

Code Python 3, 245 bytes ...
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### How to solve the LCM in 50 bytes of Python

I've recently stumbled upon a Russian site called acmp.ru, in which one of the tasks, HOK, asks us to find the LCM of two positive integers. The full statement, translated to English is as follows: ...
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### Challenge: create a large number using an esoteric programming language [duplicate]

I enjoy large numbers and esoteric programming language, so I decided to combine them into a programming challenge. Your goal is to push the limits of esoteric languages like BF or Pyth and return the ...
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### Digit small numbers

A digit small number is a positive integer $n$ such for any two numbers that multiply to $n$, their total number of digits is more than the digits in $n$. In otherwords: there are no two ...
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### Infinite ordinals from a well-ordering

Your task is to write a short program that represents a large (infinite) ordinal, using a well-ordering of the set of positive integers. Your program will take two different positive integers and ...
• 6,645
1 vote
104 views

### When the result will reach the people? [closed]

Assume the result of an exam has been published. After 5 minutes, First person knows the result. In next 5 minutes, new 8 persons know the result, and in total 9 know it. Again after 5 minutes, new 27 ...
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991 views

### Bijective meets mixed base

Background A bijective base $b$ numeration, where $b$ is a positive integer, is a bijective positional notation that makes use of $b$ symbols with associated values of $1,2,\cdots,b$. ...
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### Find the k-th order summary of a number

Background The summary of a non-negative integer $n$ is the concatenation of all digits that appear in $n$ in increasing order, with each digit being preceded by the number of times it appears in \...
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Given a positive integer $n$ and another positive integer $b$ ($1 < b < 36$), return the number of digits/length of $n$ in base $b$ ...