[seqfan] Re: LCM of sums of digits

Claudio Meller claudiomeller at gmail.com
Thu Jun 6 15:12:32 CEST 2019


What would happen if instead of taking only the sums of two numbers, we
would take all the sums possible?

Foro example if the number Is 2304 we consider
2+3= 5
2+0= 2
2+4= 6
3+0= 3
3+4= 7
0+4= 4
2+3+0= 5
2+3+4= 9
Etc

Best

El jue., 6 de jun. de 2019 01:40, Jack Brennen <jfb at brennen.net> escribió:

> There are only two solutions:  1 and 32760.
>
> Verified with a Python program that tried the LCM of every set of
> distinct positive integers <= 18.
>
>
> On 6/5/2019 11:44 PM, Frank Adams-watters via SeqFan wrote:
> > An upper bound on such numbers is 12252240, the lcm of all numbers 2
> through 18. In fact, any number with this property must be a divisor of
> 12252240. There are 480 such numbers, so the problem is easily computable.
> I'm feeling a bit too lazy to do it now; Harvey should be able to do it
> quickly.
> >
> > Franklin T. Adams-Watters
> >
> >
> > -----Original Message-----
> > From: Harvey P. Dale <hpd at hpdale.org>
> > To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
> > Sent: Wed, Jun 5, 2019 9:43 pm
> > Subject: [seqfan] Re: LCM of sums of digits
> >
> >      No additional terms up to 10^7.
> >      Best,
> >      Harvey
> >
> >
> > -----Original Message-----
> > From: SeqFan <seqfan-bounces at list.seqfan.eu> On Behalf Of Éric Angelini
> > Sent: Wednesday, June 5, 2019 6:05 PM
> > To: Sequence Discussion list <seqfan at list.seqfan.eu>
> > Subject: [seqfan] LCM of sums of digits
> >
> > Hello SeqFans,
> > Jean-Marc Falcoz discovered the
> > integer 32760 that has a  nice property.
> > Make all possible sums of two digits:
> > 3+2=5
> > 3+7=10
> > 3+6=9
> > 3+0=3
> > 2+7=9
> > 2+6=8
> > 2+0=2
> > 7+6=13
> > 7+0=7
> > 6+0=6
> > The LCM of all those sums is 32760 itself.
> > Are there more integers like this?
> > Best,
> > É.
> >
> >
> > --
> > Seqfan Mailing list -
> https://urldefense.proofpoint.com/v2/url?u=http-3A__list.seqfan.eu_&d=DwIGaQ&c=slrrB7dE8n7gBJbeO0g-IQ&r=XiYos0f3ggKs3-anzJfncQ&m=j4FZy0WM9Sl4hsEKWFnSYba-BVdfOqxoHErWDmwlOIc&s=VqH-iDICHAbzDw8mnYG5DZBQpx-PLu9p8u2btub75Ko&e=
> >
> > --
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
> > --
> > Seqfan Mailing list - http://list.seqfan.eu/
> >
> >
> >
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>



More information about the SeqFan mailing list