[seqfan] Re: Nice conjecture from Enrique Navarrete re divisors of triangular numbers A111273

[Fred Lunnon]

  By induction: if  q|(p-1)  then  q = a(q-1)  has appeared earlier; the only
divisor of  t_p  remaining is  p  itself, so  a(p-1) = p .    QED WFL



On 7/24/19, Neil Sloane <njasloane at gmail.com> wrote:
> E.N. noticed that in A111273 (definition: a(n) = smallest divisor of t_n =
> n(n+1)/2 that has not yet appeared in the sequence), it seems that a(p-1)=p
> for all odd primes p.
> Surely this can't be a hard problem?
>
> It would follow if we knew that the smallest missing number (smn) in
> A111273 (which is now A309195) is always >n/2.
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>