[seqfan] Re: A175347: Primes in A176303
Maximilian Hasler
maximilian.hasler at gmail.com
Sun Apr 18 20:20:10 CEST 2010
Oh no, thanks, but you deserve the credits for you since it was your idea.
The computation of the additional terms takes less than a minute,
with completely trivial PARI code, so it's no significant contribution.
And I don't have the time do work out a more substantial contribution.
A rather trivial observation is:
All terms (indices) must be of the form n=4k+3, because
* if n is even, then 2^n-127 = 0 (mod 3)
* If n=4k+1, then 2^n-127 = 0 (mod 5)
Regards,
Maximilian
PS: I checked that there are no more terms up to 10^4.
On Sun, Apr 18, 2010 at 7:43 PM, zak seidov <zakseidov at yahoo.com> wrote:
> Sure,
> it'd be better.
> You may wish to submit it
> (and remove A175347).
> Zak
>
>
>> From: Maximilian Hasler <maximilian.hasler at gmail.com>
>> Subject: [seqfan] Re: A175347: Primes in A176303
>> To: "Sequence Fanatics Discussion list" <seqfan at list.seqfan.eu>
>> Date: Sunday, April 18, 2010, 1:35 PM
>> Maybe it would be more "economical"
>> to list the exponents (indices of
>> A176303) rather than the primes themselves...
>> That sequence would go on:
>>
>> 47,55,103,143, 391, 2807,
>>
>> the next term is > 8000.
>>
>> Maximilian
>>
>> On Sun, Apr 18, 2010 at 6:31 PM, zak seidov <zakseidov at yahoo.com>
>> wrote:
>> > Just submitted.
>> > Zak
>> >
>> >> Subject: NEW SEQUENCE FROM submitN Zak Seidov
>> A175347
>> >
>> >> Date: Sunday, April 18, 2010, 12:40 PM
>> >
>> >> %S A175347
>> >>
>> 140737488355201,36028797018963841,10141204801825835211973625642881,
>> >> %T A175347
>> 11150372599265311570767859136324180752990081
>> >> %N A175347 Primes in A176303.
>> >> %C A175347 These are 2^n-127 for n =
>> {47,55,103,143}.
>
>>
>
>
>
>
>
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