[seqfan] Re: A073615

Harvey P. Dale hpd at hpdale.org
Wed Feb 5 18:21:21 CET 2014


Neil:
	I'm not sure that 37 works for a(5).  a(5) starts with the 6th prime (because the first prime, 2, has been discarded per the comments) which is 13.  To get 5 differences (as required for the 6th prime) we need the differences for {13, 17, 19, 23, 29, 31} which are {4, 2, 4, 6, 2}.  To get 5 differences for primes starting with 37 we need the differences for {37, 41, 43, 47, 53, 59} which are {4, 2, 4, 6, 6}.  That does not match.  If, however, we start with 223 we need the differences for {223, 227, 229, 233, 239, 241} which are {4, 2, 4, 6, 2}.  That does match.
	Have I misunderstood something?
	Best,
	Harvey

From: Neil Sloane [mailto:njasloane at gmail.com] 
Sent: Wednesday, February 5, 2014 11:53 AM
To: Sequence Fanatics Discussion list
Cc: Robert G. Wilson v; Harvey Dale
Subject: Re: [seqfan] A073615

Don, I agree that 37 seems to work for a(5).

I will make the corrections.

But the Mathematica program definitely gives 223. 
Can some Mma expert explain why?

Bob? Harvey?

Thanks

Neil

On Wed, Feb 5, 2014 at 8:04 AM, Don Reble <djr at nk.ca> wrote:
Seqfans:

   I dispute A073615(5): 37, not 223. More terms:

   5,11,13,101,37,1277,1279,1616603,57405419,51448351,76623356077,
   115438255651991,433241801791933
%C a(9) > 1734338611, a(10) = 51448351, a(11) > 131045797.

   No, yes, yes.

-- 
Don Reble  djr at nk.ca


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