## Re: Sequence

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• ... In addition, the five numbers are each one less than a prime.
Message 1 of 5 , Jan 19, 2011
--- In primenumbers@yahoogroups.com, Jack Brennen <jfb@...> wrote:
>
> Where did you get the numbers, I'm wondering...
>
> One thing I noticed was that for each of your N, sigma(N) is
> divisible by 7 and 19-smooth (no prime divisors > 19).
>
> However, there are probably thousands of other numbers less
> than 6158856 which have sigma(N) very smooth and divisible by 7,
> so there must be more to it. Still, I have to think that whatever
> these numbers have in common somehow ties in with the smoothness
> of sigma(N); the divisibility by 7 may be a coincidence.
>

In addition, the five numbers are each one less than a prime.

>
>
> On 1/17/2011 12:32 PM, Di Maria Giovanni wrote:
> > Hi
> > Does it exist a formula to generate the following numbers?
> >
> > 36
> > 540
> > 39508
> > 667332
> > 6158856
> >
> > Regards
> > Giovanni
> >
> >
> >
> >
> >
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> >