[seqfan] Re: Observation on A008328 and A205901

Frank Adams-Watters franktaw at netscape.net
Sat Jan 13 10:05:00 CET 2018


Yes, they are the same. The number of divisors of any number is odd if and only if the number is a square. The rest is trivial.

Franklin T. Adams-Watters


-----Original Message-----
From: Jeremy Gardiner <jeremy.gardiner at btinternet.com>
To: Sequence Fanatics Discussion list <seqfan at list.seqfan.eu>
Sent: Fri, Jan 12, 2018 8:14 pm
Subject: [seqfan] Observation on A008328 and A205901

It appears that run lengths of zeros in the parity of A008328 gives A205901.Checked for the 10,000 terms of A008328  given in the b-file.Parity of A008328(Number of divisors of p-1, p prime):1,0,1,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,...A205901(Number of primes between two consecutive primes of the form n^2 + 1):1, 3, 4, 13, 18, 9, 23, ...Jeremy Gardiner--Seqfan Mailing list - http://list.seqfan.eu/


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