[seqfan] Re: OEIS sequences needing factors

Neil Sloane njasloane at gmail.com
Thu Mar 21 06:56:17 CET 2013


Yes, adding it to the OEIS wiki is a great idea - I'll look into finding
the best place tomorrow
Neil

On Wed, Mar 20, 2013 at 8:43 PM, Sean A. Irvine <sairvin at xtra.co.nz> wrote:

> I'm the author of this list, readers should feel free to email me directly
> (sairvin at xtra.co.nz or sairvin at gmail.com) with new results or suggestions
> for additions to this list.  That way we can avoid cluttering up seqfan
> mailing list with lots of little updates.
>
> I can post a summary of progress or new additions every couple of months.
> Alternatively, perhaps it could just be added into the OEIS wiki somewhere.
>
> Sean.
>
>
> On 03/21/13 13:31, Charles Greathouse wrote:
>
>> Mersenneforum.org is a discussion board for those interested in
>> factorization and primality searches. I've seen the above-titled thread
>> pop
>> up a few times and I thought I would advertise it here. It comes with the
>> comment:
>>
>> **
>> Please check with corresponding OEIS entry and with factordb.com to make
>> sure number still needed before embarking on a significant effort.
>> **
>>
>> Here's the list they have now. If you have suggestions for other sequences
>> needing nontrivial factors, feel free to post there or reply here.
>>
>> id      size          description                       known ecm effort
>> ------------------------------**------------------------------**
>> --------------------
>> A000945 C335          EuclidMullin52                    7557 at 43e6
>> A000946 C332          A000946(15)                       1000 at 1m,192 at 85e7
>> A005265 C367                                            4590 at 11e6
>> A005266 C211                                            7771 at 43e6
>> A037274 C210          HP49(117)                         132 at 85e7 [likely
>> more]
>> A048986 C142          HP[2]2295                         4590 at 11e6
>> A046461 C1252       * Sm(1051)                          1000 at 1e6
>> A051308 C347          EuclidMullin[5]58                 7771 at 43e6
>> A051309 C315          EuclidMullin[11]56                7771 at 43e6
>> A051334 C328          EuclidMullin[8191]60              4590 at 11e6
>> A051335 C564          EuclidMullin[127]66               1000 at 1e6
>> A056756 C335        * EuclidMullin52                    7557 at 43e6
>> A063684 C187        * 114!+1                            17900 at 11e7
>> ,20084 at 85e7
>> A072288 Cbig        * 10^(10^100)+2, need factor > 16
>> A076670 Cbig        * (10^9)^(10^9)+1
>> A078778 C187        * 114!+1                            17900 at 11e7
>> ,20084 at 85e7
>> A078781 C265        * 151!-1                            17900 at 11e7
>> A078814 Cbig        * 10^(10^100)-7, need factor > 16
>> A080802 C265          151!-1                            17900 at 11e7
>> A080892 C241        * 3^505-2                           4590 at 11e6
>> A081715 C246        * 3^514+2                           4590 at 11e6
>> A082869 C286        * 3^599-2^599                       4590 at 11e6
>> A085745 C373        * 2^1239+1239                       7771 at 43e6
>> A085747 C158          100!+179                          4590 at 11e6
>> A087021 C242,C271   * 10^646-1
>> A096225 C106520655  * 15750503!+1
>> A093782 C429        * EuclidMullin[8581]31              4590 at 11e6
>> A094152 C398          EuclidMullin[32687]51             1000 at 1e6
>> A095194 C163          10*102!+1                         4600 at 11e6
>> A098594 C1038       * 464!+1 or C1038 464!-1            1000 at 1e6,10 at 11e6on
>> both[NEW PROGRESS]
>> A099954 C377        * F(1801) [F^R(1801) is semiprime]  15000 at 11e7
>> A100013 C154          105!+7                            4590 at 1e6
>> A101757 C288        * Tribonacci(1091)                  4590 at 11e6
>> A102050 C16385      * 10^(2^14)+1                       200 at 1e6
>> A109757 C414        * tens_complement_factorial(191)**+1
>> A109758 C183        * tens_complement_factorial(112)**-1  4590 at 11e6
>> A113773 C285        *                                   4590 at 11e6
>> A113913 C318        * 3^(3^7)+1                         1000 at 1e6,200 at 11e6
>> A115101 C387        * L(2602)                           7771 at 43e6
>> A115973 C214        * 137^137+1                         1000 at 1e6
>> A122119 C716        * 2^(2^10)+5^(2^10)                 100 at 10000
>> A125037 C2117                                           1000 at 1e6
>> A125038 C1164       *                                   1000 at 1e6
>> A125039 C160        *                                   4590 at 11e6
>> A125040 C593        *                                   1000 at 1e6
>> A125041 C160        *                                   4590 at 11e6
>> A125042 C193        *                                   4590 at 11e6
>> A125043 C1766       *                                   1000 at 1e6
>> A125044 C2995                                           1000 at 1e6[need to
>> confirm smallest before moving on]
>> A125045 C347        *                                   4590 at 11e6
>> A130139 C364        *                                   4590 at 11e6
>> A130140 C36562      *                                   100 at 10000
>> A130141 C235        *                                   4590 at 11e6
>> A153357 C148        * Wol(347)                          4590 at 11e6
>> A165767 C202        * 2^669-669                         7771 at 43e6
>> A177892 C241        *                                   4590 at 11e6
>> A181186 C162          (2^101-1)*101!+1                  1000 at 1e6
>> A181764 C187        * 114!+1                            17900 at 11e7
>> ,20084 at 85e7
>> A185121 C16385      * 10^(2^14)+1                       200 at 1e6
>> A195264 C156        * Alonso20(102)                     4600 at 11e6
>> A199295 C15151336   * 8^(8^8)+1
>> A200918 C479894     * (3^1006003-3)/1006003^2           2 at 1000,1 at 2000
>> ,1 at 5000
>> ,1 at 10000
>>
>> http://mersenneforum.org/**showthread.php?t=14265&page=3<http://mersenneforum.org/showthread.php?t=14265&page=3>
>>
>> Charles Greathouse
>> Analyst/Programmer
>> Case Western Reserve University
>>
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>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>>
>>
>
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>
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>



-- 
Dear Friends, I have now retired from AT&T. New coordinates:

Neil J. A. Sloane, President, OEIS Foundation
11 South Adelaide Avenue, Highland Park, NJ 08904, USA
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com



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