[seqfan] Re: Puzzle sequence A288573

[Frank Adams-Watters]

I can almost duplicate this

The total of the number of distinct primes in each representation of 2*n+1 as a sum of 3 primes.  I.e., a representation as p+p+p counts as 1, as p+p+q counts as 2, and p+q+r counts as 3.

This differs from the entered numbers at 2*n+1 = 25 (I get 12, entered as 11), and the final three values: I get 41,41,45 instead of 40,43,43.

Here's a PARI program. The n input to this program is the 2*n+1 in the sequence definition.

a(n)=my(p,q,r,cnt);forprime(p=3,n\3,forprime(q=p,(n-p)\2,if(isprime(r=n-p-q),cnt+=if(p===q&&p==r,1,if(p==q||q==r,2,3)))));cnt

So there are two possibilities: (1) I may have found the original definition, but there are some errors, or (2) my matching values are a coincidence. Possibility (1) is the sort of thing you would expect to see if the values were hand-computed.

Franklin T. Adams-Watters


-----Original Message-----
From: Neil Sloane <njasloane at gmail.com>
To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Sent: Wed, Jun 28, 2017 11:35 am
Subject: [seqfan] Puzzle sequence A288573

I just created A288573 for a sequence whose definition is not clear to me.
Someone was asking me why I never post anything to the OEIS page on
Facebook, so as an experiment I just posted a more detailed version of this
question there.

The Kashihara booklet where I found this sequence has a lot of other
sequences that may or may not be in the OEIS.

You can see the booklet in A288573.

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