Off-topic

[sweety439]

Like Cunningham table to various bases, is there any interest to factor the numbers similar to Fibonacci numbers A000045? e.g. Pell numbers A000129, 3-Fibonacci numbers A006190, 5-Fibonacci numbers A052918, 6-Fibonacci numbers A005668, etc. (Note: 4-Fibonacci numbers A001076 do not need their own table, since their factorization can be converted to the factorization of the Fibonacci numbers: F(4,n) = F(1,3*n)/2, like that the perfect power bases do not need their own Cunningham table. The k-Fibonacci number do not need their own table if and only if A013946(k) is the same as a previous term, like that b^n+-1 do not need their own Cunningham table if and only if A052410(b) is the same as a previous term)

[sweety439]

Some sequences like the Motzkin numbers A001006:

* Fubini numbers A000670: For n<=12000, a(n) is prime only for n = 2, 3, 5, 7, 9, 13, see A290376

* Bell numbers A000110: For n<=100000, a(n) is prime only for n = 2, 3, 7, 13, 42, 55, 2841, see A051130

* Euler zigzag numbers A000111: For n<=69574, a(n) is prime only for n = 3, 4, 6, 38, 454, 510, see A103234 (for odd n, a(n) is even, thus the only prime is a(3) = 2)

There are only very few primes in these four sequences, unlike the Fibonacci numbers A000045, the Pell numbers A000129, the Jacobsthal numbers A001045, the Perrin numbers A001608, the Padovan numbers A000931, the Narayana numbers A000930, there are many primes in these six sequences.

Can you find the next Fubini (probable) prime after A000670(13) = 526858348381?

[mathwiz]

Originally Posted by sweety439

Can you find the next Fubini (probable) prime after A000670(13) = 526858348381?

Why are you asking us? If you're interested, why don't you search for them?

[Uncwilly]

Originally Posted by mathwiz

Why are you asking us? If you're interested, why don't you search for them?

You are free to ignore any posts in this subforum. It will make your life easier.

[tuckerkao]

Originally Posted by mathwiz

Why are you asking us? If you're interested, why don't you search for them?

This thread is under Blogorrhea which has been more of the personal space granted to sweety439, just in case you don't know, sweety439 also enjoys to play around the dozenal math stuffs.

[Batalov]

Originally Posted by tuckerkao

This thread is under Blogorrhea ...

...but he didn't post here.
He posted in completely irrelevant threads - and mods (plural!) moved his non-sequiturs here.

[sweety439]

Originally Posted by charybdis

I don't know if this is the same issue that you were having, but the DB is being flooded. Someone is adding millions of 4x-digit numbers, many of the form 10^46+n, along with their factorizations, and there is now a backlog of millions of unproved small PRPs which is preventing other PRPs from being proved. I've dropped Markus an email. If the user responsible happens to be reading this forum, please could you stop?

How to (use bot to) add many numbers in a sequence to factordb? I want to add Bell(n), Euler(n), Pell(n), Tribonacci(n), BronzeFibonacci(n), Tetranacci(n), Perrin(n), Padovan(n), Narayana(n), Fubini(n), Motzkin(n), Wolstenholme(n), !(n), A(n), K(n), A000522(n), Partition(n), DistinctPartition(n), Sm(n), SmWl(n), RSm(n), RSmWl(n), and A000521(n) in factordb, for all 1<=n<=10000 (Sm(n) and SmWl(n) and RSm(n) and RSmWl(n) include their analog in bases 2<=b<=36), also the first n digits for many mathematical constants (pi, e, gamma, sqrt(2), ln(2), golden ratio, ...) in bases 2<=b<=36 for all 1<=n<=10000

(I try to use Autofill for this, but no success, for the options, I selected "JavaScript" for type and typed these texts for value:

var x = document.querySelector('input[name="query"]');
x.value = '123';
document.querySelector('[type="submit"][value="Factorize!"]').click();

var y = document.querySelector('input[name="query"]');
y.value = '456';
document.querySelector('[type="submit"][value="Factorize!"]').click();

var z = document.querySelector('input[name="query"]');
z.value = '789';
document.querySelector('[type="submit"][value="Factorize!"]').click();

(I will use PARI/GP program to change "123" and "456" and "789" to the Bell numbers, the Euler zigzag numbers, the Fubini numbers, etc. (my PARI/GP programs can compute them, and can print the codes) also all right-truncatable primes in bases 2<=b<=90 and all known minimal primes in bases 2<=b<=50 (both datas are available online), and change the variables "x" and "y" and "z" to "x1", "x2", "x3", ...)

but why the factordb only enters 789 to factorize, and does not enter 123 and 456?)

[mathwiz]

Originally Posted by Uncwilly

You are free to ignore any posts in this subforum. It will make your life easier.

The question was honest and non-rhetorical.

I am wondering why OP does not test these sequences {him,her}self. Or, if for a lack of compute resources: why are they important enough that others should test them?

[Uncwilly]

There are theoretical physics and there are experimental ones. Just maybe the person in question leans to the theoretical end of maths.

[tuckerkao]

Originally Posted by mathwiz

The question was honest and non-rhetorical.

I am wondering why OP does not test these sequences {him,her}self. Or, if for a lack of compute resources: why are they important enough that others should test them?

Sweety439 may just have his own favorite preference digging into certain areas which aren't important to other people at all.

I saw a mechanical product online recently and it showed the product number of 48-53-2837 - https://www.pinterest.com/pin/501236633550226758/

So I've decided that I want to run a PRP test of 2^48,532,837 - 1 myself(This exponent is a decimal composite but a dozenal prime with a different interpretation), my reason won't be good enough to convince anyone else, glad I have to plenty computing resources under my roof to finish it without bothering Kriesel again.

[paulunderwood]

Originally Posted by tuckerkao

So I've decided that I want to run a PRP test of 2^48,532,837 - 1 myself(This exponent is a decimal composite but a dozenal prime with a different interpretation), my reason won't be good enough to convince anyone else, glad I have to plenty computing resources under my roof.