Peter Košinár's user avatar
Peter Košinár's user avatar
Peter Košinár's user avatar
Peter Košinár
  • Member for 10 years, 9 months
  • Last seen this week
30 votes

"Integer average" of two integer numbers

13 votes

What is the smallest integer $n$>1 such that $n^{5000}+n^{2013}+1$ is prime?

12 votes

System of linear equations having a real solution has also a rational solution.

12 votes
Accepted

Identity for $e$ in terms of the Fibonacci sequence.

11 votes

Generating all coprime pairs within limits

11 votes
Accepted

Why is NP not equal to P^NP?

11 votes
Accepted

Is a finite tiling of 45-45-90 triangles uniquely determined from the resulting union (up to trivial flips)?

10 votes

Why is the Fibonacci ratio though a decreasing function, it is alternating and decreasing?

9 votes
Accepted

Narcissistic numbers in other bases

9 votes
Accepted

How prove this sum $1+\sum_{n=1}^{\infty}(1+x^n)(\frac{(1-y)(1-yx)(1-yx^2)\cdots(1-yx^{n-1})}{(y-x)(y-x^2)(y-x^3)\cdots(y-x^n)}=0$

8 votes
Accepted

Integer coefficient polynomial - values as powers of 2

8 votes
Accepted

What is the smallest real $q$ such that there is always a prime between $n^q$ and $(n+1)^q?$

8 votes
Accepted

About the sum of the digits of $k^{105}$.

8 votes
Accepted

Problem about functional equations: $ f \left( x ^ 2 + y \right) = f ( x ) ^ 2 + \frac { f ( x y ) } { f ( x ) } $

7 votes
Accepted

Is polynomial $1+x+x^2+\cdots+x^{p-1}$ irreducible?

7 votes
Accepted

Evaluate complicated sum $\sum \sum {n \choose k}{n-k \choose l}(j-i-1)^{n-k-l}.$

7 votes
Accepted

Special number near $5^{5^3}$

7 votes

Commutativity of Ordinal Multiplication

6 votes

Is $1847^{2013}+2$ really a prime?

6 votes
Accepted

About a particular polynomial function

6 votes
Accepted

Value minimizing mean absolute percentage error

5 votes

prove or disprove $P_{i}\cdot P_{k+1-i}>P_{k+1}$

5 votes
Accepted

Is this backwards reasoning?

5 votes
Accepted

Sum of polynomial

5 votes
Accepted

How can I find which function corresponds to a set of data points?

5 votes

Bertrand's postulate in another point of view

5 votes
Accepted

Chaos in finite field

5 votes
Accepted

Conjecture on cycle length and primes

5 votes
Accepted

Square-Trangular Numbers Checking Answer

5 votes
Accepted

Probability of getting into my favorite PhD

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