# Questions tagged [math]

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

1,651 questions
Filter by
Sorted by
Tagged with
1k views

164 views

2k views

### Delannoy numbers

Consider a grid from $(0,0)$ in the bottom-left corner to $(m,n)$ in the top-right corner. You begin at $(0,0)$, and can only move in one of these three ways: Directly north $(+0, +1)$, ...
924 views

1k views

### You are kinda Replacable to Me

You are provided with a non-empty array $A$ of integers, all greater than 0. But what good is an array if the elements do not sum up to the number $N$ (also provided as input)... So to change that,...
594 views

### The half-step of Fibonacci

Challenge Implement the 1-indexed sequence A054049, which starts like this: ...
2k views

### How many bystanders will help?

Flavortext The Bystander Effect is a phenomenon where individuals are less likely to help a victim if other people are present. The idea is that as there are more people around, the individual burden ...
2k views

### How hyperperfect am I?

A $k$-hyperperfect number is a natural number $n \ge 1$ such that $$n = 1 + k(\sigma(n) − n − 1)$$ where $\sigma(n)$ is the sum of the divisors of $n$. Note that $\sigma(n) - n$ is the ...
1k views

### Calculate Home Primes

The Home Prime of an integer $n$ is the value obtained by repeatedly factoring and concatenating $n$'s prime factors (in ascending order, including repeats) until reaching a fixed point (a prime). ...
1k views

### The meeker number sequence

The Meeker numbers are a 7 digit number in form of $abcdefg$, where $a×b=10c+d$ and $d×e=10f+g$. As an example $6742612$ is a meeker number, here $6×7=10×4+2$ and $2×6=10×1+2$, so it is a ...
520 views

### Determine Circles

Giving n(any amount) of points (x,y). What's the minimum amount of circles required to cross every point given? Task Your ...
1 vote
213 views

### A problem of rarity [closed]

Given a positive input $n > 0$, output the amout of two types based on their rarity. The two types are called $A$ and $B$, we know the followings: $n$ is a limited input and the maximum is ...
1k views

### Multiplicative Persistence #2

We had a challenge on Multiplicative Persistence here. As a recap, to get a multiplicative persistence of a number, do these steps: Multiply all the digits of a number (in base $10$) Repeat Step 1 ...
2k views

### Implement Ash's float division

Ash has a bit of an interesting float division algorithm. It's designed to never return NaN, and things like signed zero and infinity need to be handled. How it ...
520 views

2k views

### Quoted rational numbers

Quote notation is a way of expressing rational numbers based on the concept of $p$-adic numbers, written in the form $x'y$. The quote indicates that the number to it's left ($x$) is "...