[seqfan] Re: More (composite) terms for A233281: 4181, 10877, 75077, ?

Charles Greathouse charles.greathouse at case.edu
Tue Feb 4 15:19:30 CET 2014


Yes, I think those terms are enough -- though don't forget keyword:bref in
addition to more.

Of the names you suggest for A233281, I prefer the original, or something
like it:

Numbers n such that the least Fibonacci number F_k which is a multiple of n
has a prime index, i.e., A001177(n) is prime.

Charles Greathouse
Analyst/Programmer
Case Western Reserve University


On Tue, Feb 4, 2014 at 6:33 AM, Antti Karttunen
<antti.karttunen at gmail.com>wrote:

> On Tue, Feb 4, 2014 at 10:33 AM,  <seqfan-request at list.seqfan.eu> wrote:
>
> > Message: 11
> > Date: Mon, 3 Feb 2014 17:58:22 -0500
> > From: Hans Havermann <gladhobo at teksavvy.com>
> > To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> > Subject: [seqfan] Re: More (composite) terms for A233281
> > Message-ID: <AB7E92A4-83F8-45C8-A738-8236C60CC0A4 at teksavvy.com>
> > Content-Type: text/plain; charset=us-ascii
> >
>
> > "Numbers n such that the least Fibonacci number F_k which is a multiple
> of n has a prime index, i.e. k is in A000040."
> >
> ...
> > Anyways, here are some additional values less than 10^8: 75077, 162133,
> 330929, 1256293, 1346269, 2662277, 3636121, 4226777, 9401893, 13455077,
> 14787181, 16485493, 21692189, 24157817, 24493061, 25532501, 29604893,
> 31432381, 39247393, 73780877, 75245777, 77337941.
> >
> > 75077 is the only additional composite < 10^5. In the remaining range, I
> don't know if there are other solutions.
> >
>
> Thank you Hans!
>
> CC: Neil,
>
> is here enough terms:
> 4181, 10877, 75077
> to submit it as as sequence of its own? (with keyword:more )
> "Composite numbers n such that A001177(n) is prime."
> (A subset of http://oeis.org/A233281 )
> Again, people are free to invent better names/definitions.
>
>
> BTW, All are members of various Lucas / Frobenius pseudoprimes sequences:
> https://oeis.org/search?q=4181+10877+75077&sort=&language=&go=Search
>
>
> As what comes to the name of A233281, Hans objected its current version:
>
> > "Numbers n such that the least Fibonacci number F_k which is a multiple
> of n has a prime index, i.e. k is in A000040."
> >
> > For those of us who think 'multiple' means more than one, 'positive
> multiple' (or an example) might have cleared this up.
>
> Actually, I considered also these alternative names:
>
> Numbers n such that the least p satisfying n|F_p (where F_p is p-th
> Fibonacci number) is prime.
>
> Numbers n such that the least p satisfying F_p = x*n (where F_p is
> p-th Fibonacci number) is prime.
>
> Numbers n such that the least k which satisfies {F_k = 0 mod n} is
> prime, where F_k is k-th Fibonacci number.
>
> Numbers n such that the least Fibonacci number F_k which satisfies
> {F_k = 0 mod n} is Fibonacci number F_k with a prime index k.
>
>
> Vote for the best or suggest a better one?
>
>
> Yours,
>
> Antti
>
> >
> > On Feb 1, 2014, at 9:08 PM, Antti Karttunen <antti.karttunen at gmail.com>
> wrote:
> >
> >>> http://oeis.org/A233281 that I recently submitted: "Numbers n such
> that A001177(n) is prime."
> >>> So far, only two composites there, 4181 and 10877, are known.
> >
> >
>
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