User José María Grau Ribas

11 votes

3 answers

1k views

What is the limit of $a (n + 1) / a (n)$?

asked Apr 1, 2021 at 9:46

6 votes

1 answer

498 views

Do you know which is the minimal local ring that is not isomorphic to its opposite?

asked Nov 14, 2020 at 9:12

4 votes

0 answers

227 views

Do you know rings without involutions, auto-anti-isomorphics? In that case, what is the minimal example?

asked Mar 7, 2021 at 11:41

3 votes

1 answer

238 views

Number of rings with additive group $(\mathbb{Z}_{16})^2$. A341547(16) in OEIS

asked Apr 5, 2021 at 8:33

3 votes

1 answer

304 views

A generating function related to the Delannoy numbers

asked Jul 23, 2021 at 16:22

3 votes

1 answer

144 views

About the sequence $s_n:=f_{n,n} $ where $f_{0,n}=f_{n,0}= n^n$ and $f_{m,n} = f_{m-1,n}+ f_{m,n-1} + f_{m-1,n-1}$

asked Jul 28, 2021 at 15:34

2 votes

0 answers

122 views

Existence and uniqueness of solution of a nonlinear system

asked Jun 30, 2021 at 9:16

1 vote

2 answers

331 views

How many non-isomorphic associative algebras of dimension 2 over the field F_{p^k} are there?

asked Feb 10, 2021 at 11:10

1 vote

0 answers

193 views

Why $\lim_{n\rightarrow \infty}\frac{F(n,n)}{F(n-1,n)} =\lim_{n\rightarrow \infty}\frac{F(n+1,n)}{F(n,n)} $?

asked Apr 10, 2021 at 5:29

1 vote

1 answer

340 views

Why $\lim_{n\rightarrow \infty}\frac{F(n,n)}{F(n-1,n-1)} =\frac{9}{8}$?

asked Apr 22, 2021 at 19:58

1 vote

1 answer

146 views

Do you know a finite unitary reversible ring that is not isomorphic to its opposite? And the minimal with that property?

asked Mar 9, 2021 at 12:12

1 vote

1 answer

115 views

Limit of $F_{n}(\lfloor{nx}\rfloor)$ where $ F_{n}(k)=G_{n}(k)+H_{n}(k)F_{n}(k+1) $ and $F_{n}(n)=\mu.$

asked Jan 31 at 13:45

0 votes

1 answer

248 views

Given a unitary commutative ring $R$, what are the rings $R\langle x,y\rangle/(x^2-A,y^2-B,yx-a-bx-cy-dxy)$ called

asked Mar 11, 2021 at 11:44

0 votes

1 answer

125 views

What is the computational complexity of the calculation of $ \Psi(x) $?

asked Mar 12, 2021 at 7:58

0 votes

1 answer

154 views

How to probe the recursiveness order of a sequence $\{S_n\}$ whose generating function is known

asked Jun 15, 2021 at 13:18

0 votes

0 answers

112 views

Is the sequence $s_n:=f_{n,n} $ where $f_{0,n}=f_{n,0}= n!$ and $f_{m,n} = f_{m-1,n}+ f_{m,n-1} + f_{m-1,n-1}$ P-recursive?

asked Jul 14, 2021 at 20:32

0 votes

1 answer

105 views

Do you know of any indecomposable ring that has no isolated elements and is neither reversible, nor integral, nor nilpotent, nor unitary?

asked Sep 15, 2022 at 6:23

-4 votes

1 answer

301 views

Limit of recursion relation

asked Jan 26, 2023 at 9:51

Stack Exchange Network

18 Questions

What is the limit of $a (n + 1) / a (n)$?

Do you know which is the minimal local ring that is not isomorphic to its opposite?

Do you know rings without involutions, auto-anti-isomorphics? In that case, what is the minimal example?

Number of rings with additive group $(\mathbb{Z}_{16})^2$. A341547(16) in OEIS

A generating function related to the Delannoy numbers

About the sequence $s_n:=f_{n,n} $ where $f_{0,n}=f_{n,0}= n^n$ and $f_{m,n} = f_{m-1,n}+ f_{m,n-1} + f_{m-1,n-1}$

Existence and uniqueness of solution of a nonlinear system

How many non-isomorphic associative algebras of dimension 2 over the field F_{p^k} are there?

Why $\lim_{n\rightarrow \infty}\frac{F(n,n)}{F(n-1,n)} =\lim_{n\rightarrow \infty}\frac{F(n+1,n)}{F(n,n)} $?

Why $\lim_{n\rightarrow \infty}\frac{F(n,n)}{F(n-1,n-1)} =\frac{9}{8}$?

Do you know a finite unitary reversible ring that is not isomorphic to its opposite? And the minimal with that property?

Limit of $F_{n}(\lfloor{nx}\rfloor)$ where $ F_{n}(k)=G_{n}(k)+H_{n}(k)F_{n}(k+1) $ and $F_{n}(n)=\mu.$

Given a unitary commutative ring $R$, what are the rings $R\langle x,y\rangle/(x^2-A,y^2-B,yx-a-bx-cy-dxy)$ called

What is the computational complexity of the calculation of $ \Psi(x) $?

How to probe the recursiveness order of a sequence $\{S_n\}$ whose generating function is known

Is the sequence $s_n:=f_{n,n} $ where $f_{0,n}=f_{n,0}= n!$ and $f_{m,n} = f_{m-1,n}+ f_{m,n-1} + f_{m-1,n-1}$ P-recursive?

Do you know of any indecomposable ring that has no isolated elements and is neither reversible, nor integral, nor nilpotent, nor unitary?

Limit of recursion relation