# [seqfan] Re: A268539: Primes in

Zak Seidov zakseidov at mail.ru
Sat Mar 5 22:53:15 CET 2016

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Also, A(n)=A(n-4)+24, see Comments by   M. F. Hasler  in A268539.
Zak
>Среда,  2 марта 2016, 21:21 -06:00 от "Bob Selcoe" <rselcoe at entouchonline.net>:
>
>Hi Robert, Zak and Seqfans,
>
>>>>Each term of A268539 is of the form (x^2-25)/48 = (x-5)(x+5)/48
>
>Unless I'm mistaken, the values of x in Robert's equation are sequence A(x)
>starting a(1)=5 with periodic first differences of [6,2,6,10], so A(x) =
>5,11,13,19,29,35,37,43,53,59,61,67,77,83,85...
>
>Might make for an interesting entry??
>
>Cheers,
>Bob Selcoe
>
>--------------------------------------------------
>From: < israel at math.ubc.ca >
>Sent: Wednesday, March 02, 2016 7:56 PM
>To: "Sequence Fanatics Discussion list" < seqfan at list.seqfan.eu >
>Subject: [seqfan] Re: A268539: Primes in
>
>> On Mar 2 2016, Zak Seidov wrote:
>>
>>>  https://oeis.org/A268539
>>>Are 2,3,7,17 the only primes in A268539?
>>>
>>>--
>>>Seqfan Mailing list -  http://list.seqfan.eu/
>>>
>>
>> Yes.  Each term of A268539 is of the form (x^2-25)/48 = (x-5)(x+5)/48
>> where x is an integer.  So if x > 53, it must factor...
>>
>> Cheers,
>> Robert
>>
>> --
>> Seqfan Mailing list -  http://list.seqfan.eu/
>>
>
>--
>Seqfan Mailing list -  http://list.seqfan.eu/

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