[seqfan] Re: Subtract if prime, else add

[Lars Blomberg]

I have updated A309529 with graphs of 10^8 terms.
/Lars

-----Ursprungligt meddelande-----
Från: SeqFan <seqfan-bounces at list.seqfan.eu> För Neil Sloane
Skickat: den 7 augusti 2019 17:45
Till: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Ämne: [seqfan] Re: Subtract if prime, else add

Eric, A309529 and A309521 are an interesting pair of sequences!

For A309529 (I did a bit of editing), it would be interesting to see what happens when we look at more terms - does the sequence stay positive, or does it go negative again at some point?

Maybe Lars could look at it?  It would be interesting to see the graphs of the first X terms, for some large values of X !

For the "primes" version, A309521 (again I did some editing), now that it has been approved, we need a b-file!  Lars's comments suggest that this one is going to keep growing for ever, unlike the first sequence.


Best regards
Neil

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



On Tue, Aug 6, 2019 at 6:24 AM Éric Angelini <eric.angelini at skynet.be>
wrote:

> Lars, be blessed among the blessed!
> I will submit this asap to the OEIS!
>
> à+
> É.
> Catapulté de mon aPhone
>
>
> > Le 6 août 2019 à 10:43, Lars Blomberg <larsl.blomberg at comhem.se> a
> écrit :
> >
> >
> > Up to 10^6 the terms increase approximately linearly, no cycles are
> visible.
> > The last terms are
> > 3590238, 3590240, 3590242, 3590248, 3590251, 3590251, 3590257, 
> > 3590259,
> 3590261, 3590267, 3590270, 3590279, 3590285, 3590287, 3590289, 
> 3590295, 3590298, 3590306, 3590312, 3590314, 3590316, 3590322, 
> 3590326, 3590326, 3590332, 3590334, 3590336, 3590342, 3590346
> >
> > Small values not encountered
> > 2, 3, 6, 7, 13, 14, 19, 20, 24, 30, 31, 32, 33, 34, 35, 37, 39, 40, 
> > 41,
> 42, 43, 44, 46, 49, 51, 53, 55, 56, 57, 58, 59, 60, 61, 66, 67, 68, 
> 69, 70, 75, 76, 77, 78, 79, 80, 81, 83, 85, 86, 87, 88, 89, 90, 91, 
> 92, 100, 108, 109, 110, 113, 114, 115, 116, 117, 118
> > (same as for 1000 terms)
> >
> > /Lars
> >
> >
> >
> > --
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>
>
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