[seqfan] Re: A203025

Olivier Gerard olivier.gerard at gmail.com
Fri Jun 3 08:04:51 CEST 2016


The usual policy of the encyclopedia goes clearly in the direction of your
first solution.

I think you should revert to the original values, replace the b-file and a
create a new sequence
for the second one as I don't think it exists independently in the OEIS.

Here is a Mathematica Program to replace Tony Noe's in A203025.
It gives the original sequence (notably 36 for n=36 and 72 and 100 for 100).

Table[If[SquareFreeQ[n], 1, s = FactorInteger[n];
  Max[Table[Times @@ Cases[s,
      {p_, ep_} :> p^i /; (ep >= i)], {i, 2, Max[s[[All, 2]]]}]]], {n,
   100}]

{1, 1, 1, 4, 1, 1, 1, 8, 9, 1, 1, 4, 1, 1, 1, 16, 1, 9, 1, 4, 1, 1,
1, 8, 25, 1, 27, 4, 1, 1, 1, 32, 1, 1, 1, 36, 1, 1, 1, 8, 1, 1, 1, 4,
9, 1, 1, 16, 49, 25, 1, 4, 1, 27, 1, 8, 1, 1, 1, 4, 1, 1, 9, 64, 1,
1, 1, 4, 1, 1, 1, 36, 1, 1, 25, 4, 1, 1, 1, 16, 81, 1, 1, 4, 1, 1, 1,
8, 1, 9, 1, 4, 1, 1, 1, 32, 1, 49, 9, 100}


Olivier


On Fri, Jun 3, 2016 at 5:06 AM, Frank Adams-Watters <franktaw at netscape.net>
wrote:

> There is a problem with this sequence, and I'm not sure which way to go
> with it.
>
> https://oeis.org/A203025 is titled "Largest perfect power divisor of n. "
> Up until January 2012, that's what it was, and the comments still reflect
> that. However, at that time a Mathematica program was added which fits the
> definition "Largest proper prime power divisor of n, or 1 if n is
> square-free". The values in the sequence were changed to this definition,
> and a b-file added with this definition.
>
> I guess I'm inclined to revert to the original values, junk that program,
> and replace the b-file. Any opinions on that? Should we then add the
> sequence which matches the current values, but with a correct name? If
> instead we keep the current values, should we then add the sequence as
> originally defined?
>
> Note: the PARI program does appear to produce the originally defined
> sequence.
>
> Franklin T. Adams-Watters
>
>
> --
> Seqfan Mailing list - http://list.seqfan.eu/
>


More information about the SeqFan mailing list