[seqfan] OEIS sequences needing factors
Charles Greathouse
charles.greathouse at case.edu
Thu Mar 21 01:31:52 CET 2013
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 11e6 on
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
Charles Greathouse
Analyst/Programmer
Case Western Reserve University
More information about the SeqFan
mailing list