[seqfan] Re: A106464

Peter Munn techsubs at pearceneptune.co.uk
Fri May 11 20:36:37 CEST 2018

On Fri, May 11, 2018 5:56 am, Don Reble wrote:
>> ...why don't we ask Paul Barry... ?
>     Ok. Paul, is the summed triangle A003989, and should the
>     formula be a(n)=sum{k=0..floor(n/2), gcd(n-k+2, k+1)} ?

A003989 seems likely (the diagonals can be seen its display as an upper
right triangle), as Paul appears to have submitted on the same day three
other sequences that referred to A003989: A106465, A106473 and A106475.

A029578 was another sequence Paul was dealing with. It is referred to by
A106465, and another sequence he submitted on that date, A106472 (in these
cases correctly, it seems to me).

Best Regards,


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