[seqfan] Re: A245486

[hv at crypt.org]

For (2), if I understand correctly, 46 will not appear: for a factor of
2 to show, we need n = 2^k or n = 2^k - 1 for some k, and we then need
23 to be the greatest prime factor of 2^k + 1 or 2^k - 1 respectively;
but I think 23 never divides 2^k + 1, and is never the greatest prime
dividing 2^k - 1 (since it is always paired with 89).

Hugo

Frank Adams-Watters <franktaw at netscape.net> wrote:
:I have a new sequence in editing state: https://oeis.org/draft/A245486 
:- Greatest prime factor of n times greatest prime factor of n+1.
:
:1) I think it's the case that recent results show that this sequence 
:goes to infinity; equivalently, each member of A006881(products of 2 
:distinct primes) occurs only finitely many times. Can someone confirm 
:this?
:
:2) I can almost prove that every member of A006881 does occur in this 
:sequence. Can anyone find a proof? (Or a counterexample.)
:
:Franklin T. Adams-Watters
:
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