Unsolved Problems

Showing 651-662 of 662 problems (Page 14 of 14)

EP-1110
Open

Erdős Problem #1110

Let $p>q\geq 2$ be two coprime integers. We call $n$ representable if it is the sum of integers of the form $p^kq^l$, none of which divide each other....

L1
Number Theory
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0
EP-1111
Open

Erdős Problem #1111

If $G$ is a finite graph and $A,B$ are disjoint sets of vertices then we call $A,B$ anticomplete if there are no edges between $A$ and $B$. If $t,c\ge...

L1
Graph Theory
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0
EP-1112
Open

Erdős Problem #1112

Let $1\leq d_1<d_2$ and $k\geq 3$. Does there exist an integer $r$ such that if $B=\{b_1<\cdots\}$ is a lacunary sequence of positive integers with $b...

L1
Number Theory
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0
EP-1113
Open

Erdős Problem #1113

A positive odd integer $m$ such that none of $2^km+1$ are prime for $k\geq 0$ is called a Sierpinski number. We say that a set of primes $P$ is a cove...

L1
Number Theory
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0
EP-1117
Open

Erdős Problem #1117

Let $f(z)$ be an entire function which is not a monomial. Let $ u(r)$ count the number of $z$ with $\lvert z\rvert=r$ such that $\lvert f(z)\rvert=\ma...

L1
Combinatorics
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0
EP-1120
Open

Erdős Problem #1120

Let $f\in \mathbb{C}[z]$ be a monic polynomial of degree $n$, all of whose roots satisfy $\lvert z\rvert\leq 1$. Let $ E= \{ z : \lvert f(z)\rvert \le...

L1
Graph Theory
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0
EP-1122
Open

Erdős Problem #1122

Let $f:\mathbb{N}\to \mathbb{R}$ be an additive function (i.e. $f(ab)=f(a)+f(b)$ whenever $(a,b)=1$). Let $ A=\{ n \geq 1: f(n+1)< f(n)\}. $ If $\lver...

L1
Combinatorics
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0
EP-1129
Open

Erdős Problem #1129

For $x_1,\ldots,x_n\in [-1,1]$ let $ l_k(x)=\frac{\prod_{i eq k}(x-x_i)}{\prod_{i eq k}(x_k-x_i)}, $ which are such that $l_k(x_k)=1$ and $l_k(x_i)=0$...

L1
Geometry
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0
EP-1130
Open

Erdős Problem #1130

For $x_1,\ldots,x_n\in [-1,1]$ let $ l_k(x)=\frac{\prod_{i eq k}(x-x_i)}{\prod_{i eq k}(x_k-x_i)}, $ which are such that $l_k(x_k)=1$ and $l_k(x_i)=0$...

L1
Combinatorics
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0
EP-1131
Open

Erdős Problem #1131

For $x_1,\ldots,x_n\in [-1,1]$ let $ l_k(x)=\frac{\prod_{i eq k}(x-x_i)}{\prod_{i eq k}(x_k-x_i)}, $ which are such that $l_k(x_k)=1$ and $l_k(x_i)=0$...

L1
Combinatorics
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0
EP-1132
Open

Erdős Problem #1132

For $x_1,\ldots,x_n\in [-1,1]$ let $ l_k(x)=\frac{\prod_{i eq k}(x-x_i)}{\prod_{i eq k}(x_k-x_i)}, $ which are such that $l_k(x_k)=1$ and $l_k(x_i)=0$...

L1
Combinatorics
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0
EP-1133
Open

Erdős Problem #1133

Let $C>0$. There exists $\epsilon>0$ such that if $n$ is sufficiently large the following holds. For any $x_1,\ldots,x_n\in [-1,1]$ there exist $y_1,\...

L1
Graph Theory
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0