Go Back > Extra Stuff > Blogorrhea > MattcAnderson

Thread Tools
Old 2021-06-15, 07:34   #1
MattcAnderson's Avatar
"Matthew Anderson"
Dec 2010
Oregon, USA

2×3×151 Posts
Thumbs up fun with

Tonight I found that a C75 is a P32 times a P44.

It required 165.14 seconds of computer time,
Using Maple 13 student version
and my computer is
Windows 7 Home Premium, service pack 1
(stable but fighting update suggestions)
Dell Studio XPS 8100
Intel(R) Core(TM) i7 CPU 870 @ 2.93GHz
(not overclocked not dusty no current heat issues)
8.00 GB Installed memory (RAM)
64-bit Operating System
(no kids in the house, have wife and dog (Annabel - see pets post for picture))
(possible roommate in future. Paying tenant. Want more vacation and
restaurant meals. )

anyway enough with the personal part. Here is the exciting -

Before I added data, the C75 was determined composite and was
definitely not of unknown character (prime or composite).



P32 and P44

48513722976304242000153731071441<32> · 15557952343130679147755701144328513488043029<44>

Going to eat now.
Attached Thumbnails
Click image for larger version

Name:	factor_d_b.png
Views:	44
Size:	239.7 KB
ID:	25123  
MattcAnderson is offline   Reply With Quote
Old 2021-06-15, 07:57   #2
MattcAnderson's Avatar
"Matthew Anderson"
Dec 2010
Oregon, USA

11100010102 Posts

Found a C70


away from keyboard


P14 * P28 * P29

62936542414259<14> · 3721001974321543266672687967<28> · 22424797223486196447937965793<29>

Did this before, some years ago when I was working on Prime Constelations.
Originall calculations for our online encyclopedia of integer sequences dot org

This website is in the style of wikipedia and is owned by google so I can no longer make changes to it.

However, I have backed it up, on little Universal Serial Bus (USB) memory storage device
(thumbnail hardware)

Good fun

Last fiddled with by MattcAnderson on 2021-06-15 at 08:26 Reason: added link and gave more details
MattcAnderson is offline   Reply With Quote
Old 2021-06-15, 08:29   #3
MattcAnderson's Avatar
"Matthew Anderson"
Dec 2010
Oregon, USA

90610 Posts

Now a C67


so interesting

and useful in at least 3 millennia as we continue to colonize Mars.

good mathematical trivia

away from keyboard again
MattcAnderson is offline   Reply With Quote
Old 2021-06-15, 16:57   #4
MattcAnderson's Avatar
"Matthew Anderson"
Dec 2010
Oregon, USA

2·3·151 Posts

Now an previously unknown C83 is a P36 times a P48

To show


134954146509066228002222828521591151<36> · 282663928443552831960531852882219045579470788747<48>

As usual, Maple computer algebra system does the calculation.

A second calculation, where I used my computing power for the common good.


So a C83 is a P57 times a P26

Two calculations for the price of one.

Now a third calculation
# a C72 needing factoring
> ifactor(431951947630596321658466238929565258017885765694269056314003364436248649);
print(`output redirected...`);
# input placeholder
(232353028381758099222878389962317) (1859033000942408277227568406797114146797)

# calculation number 4
# an easy C72
> ifactor(165899983662255688471809882590614582299651829639766394486046093934534531);


That is P20 * P25 * P28

# C63 needs factorization
> ifactor(138152297859254560882099296463904468254265421713121317806141139);

(3355920492373395691681335541) (41166737463899093611930167715437479)

and only a few tens of seconds of computer time.

another one
# C63 factored and reported to
> ifactor(189538484332123294045600201844861506643780749140978223831637939);
print(`output redirected...`); # input placeholder
(143820796667507966711791845013) (1317879532890557820822643382123303)

# only 20 seconds of computation time on this one.

another one
# C60 factored and reported to
> ifactor(151996640445840293245405079864773923954627764256609641566429);
print(`output redirected...`); # input placeholder
(24285925367577446693795141) (6258630797274913966996966660483769)

this C60 factored in under 7 seconds of computation time.

another one
61493390605085032632697975887667162345441<41> = 1103526119<10> · 55724454135086070067633782837239<32>
this includes the digit count at the end of the numbers.
less than a minute of computation time. Awesome.

another one
# a C74 factored and reported to
# 131 second computation time on this one
> ifactor(24582591584604460062256786284620852944170003807267337840218983547251269109);

(35183656999490713445063) (698693475353067910344746424750961346480505668287843)
so we see C74 = P23*P51.
totally awesome

another one
# C80 factored and reported to


another one A C25 factors into a P17 and a P9. Specifically,
> ifactor(4061175182312812557675533);

(359831579) (11286322322235127)
And database and website did not know this answer until I told it.
It took less than a second of computation time.

another one, a C68 is fully factored with a P21 and a P47
> ifactor(29033656705936299898290356598350209400998240054447587486839502132031);

(751343048685549742241) (38642344208454099899513077332898081508596404191)
calculated in 42 seconds of computer calculation. did not know this result until I told it.
That database is gaining data.

pretty quick

here is another one. A C76 that was factored by my computer in 1 minute and 58 seconds, quick.


= 171206516971178333556612731<27> * 31138548015886995766862127463540612963975610677807<50>

To be sure, a C76 = P27 * P50.

another one
A C61 factors as a P19, a P20, and a P23.
Note that
19 + 20 + 23 = 62, which is very close to 61.
= 2305728636742600703<19> · 65204944046653124213<20> · 59941000602693444703933<23>.

It is interesting to consider numbers near a googol. A googol is a number with 101 digits.
10^100+91<101> = 79 · 6880726549933<13> · 5068013823241573808081<22> · 154972061606042703135868972981<30> · 23423263752533621617530706402640533<35>
very interesting

here is another one
> ifactor(72087326271153459481230176223024266382449693517548185641957020283436256653774674334563461);

(126099801428594826245322089) (571668832579197769805225819739758331955032068099267073705909949)

So a C89 is a P27 times a P63 in disguise :--)
This calculation took less than 66 minutes with my Maple tool.


see attached - Maple to factor integers.pdf
Lots of fun.

Attached Files
File Type: pdf Maple to factor integers.pdf (126.5 KB, 39 views)

Last fiddled with by MattcAnderson on 2021-06-21 at 03:48 Reason: 6th calculation
MattcAnderson is offline   Reply With Quote
Old 2021-06-15, 18:20   #5
6809 > 6502
Uncwilly's Avatar
Aug 2003
101×103 Posts

271816 Posts

Maybe you should gather your work up for 1 week and then post your results. Posting minor updates frequently is tiresome.
Uncwilly is offline   Reply With Quote
Old 2021-08-17, 04:20   #6
MattcAnderson's Avatar
"Matthew Anderson"
Dec 2010
Oregon, USA

2·3·151 Posts

Hi all,

I have been doing several requested integer factorizations for

Some composites are semi-primes, that is of the form composite = prime1 * prime2.

My last one was

(10^71+33123)/14219691071<61> = 12684852287106422167790489<26> · 554401535483277901401800643095782117<36>

Sometimes the numbers are 10,000-smooth and have many factors.
Those numbers take much less computation time

Still fun.

MattcAnderson is offline   Reply With Quote
Old 2021-09-23, 10:34   #7
MattcAnderson's Avatar
"Matthew Anderson"
Dec 2010
Oregon, USA

2×3×151 Posts
Smile more calculations

Hi again all,

I have probably done over 50 quick calculations for In My Humble Opinion, this is a useful database. Now we know that a C74 is a P22 times a P24 times a P29. Specifically,

(2123766^17-1)/4830869344730522132314982799853985 <74> =
3995338558734555154151<22> · 483489332374281832645177<24> · 38980509326442350080033766609<29>

this calculation took 135 seconds on my Intel i7, 2.93 GHz computer.

Good fun

MattcAnderson is offline   Reply With Quote

Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
A suggestion for factordb. enzocreti FactorDB 19 2021-08-11 16:49
Other Factordb Problems wblipp FactorDB 472 2021-08-05 03:42
Spammers in FactorDB wpolly FactorDB 5 2019-04-16 11:19
Extending Factordb carpetpool FactorDB 6 2017-01-23 11:04
FactorDB PRP's smh FactorDB 231 2015-07-28 02:30

All times are UTC. The time now is 19:15.

Thu Oct 21 19:15:50 UTC 2021 up 90 days, 13:44, 1 user, load averages: 2.71, 2.00, 1.70

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.