[seqfan] Re: Maple program

Brendan McKay Brendan.McKay at anu.edu.au
Sun Oct 25 02:16:38 CET 2020


A one-liner is

select(n -> max(numtheory[factorset](n^3-1)) <= n, [seq(i, i=2..400)]);

Brendan.

On 25/10/20 2:56 am, Frank Adams-watters via SeqFan wrote:
> Thank you, Brendan. That does answer my question. Given that behavior by Maple, I agree with the program as it is.
>
> Franklin T. Adams-Watters
>
>
> -----Original Message-----
> From: Brendan McKay <Brendan.McKay at anu.edu.au>
> To: seqfan at list.seqfan.eu
> Sent: Fri, Oct 23, 2020 9:02 pm
> Subject: [seqfan] Re: Maple program
>
> After   isA081258 := n -> max(numtheory[factorset](n^3-1)) <= n,
> isA081258(10) returns "37 <= 10", not false.  This is OK in this
> example because it is evaluated as false by the 'if' statement in
> the following loop.
>
> It isn't OK in general.  For example even though isA081258(10)
> and isA081258(11) are both false inequalities, the test
>     isA081258(10) = isA081258(11)
> evaluates as false even in an 'if' statement.
>
> If you actually want an actual false or true value,
>     isA081258 := n -> evalb(max(numtheory[factorset](n^3-1)) <= n)
> will do it.
>
> (tested in Maple 2018)
>
> Brendan.
>
>
> On 24/10/20 4:16 am, israel at math.ubc.ca wrote:
>> There is no reason.  Even simpler would be
>>
>> isA081258 := n -> max(numtheory[factorset](n^3-1)) <= n:
>>
>> Cheers,
>> Robert
>> On Oct 23 2020, Frank Adams-watters via SeqFan wrote:
>>
>>> I'm looking at A081258. The Maple program there has the statement:
>>>
>>>         if max(op(%)) <= n then
>>>                 true;
>>>         else
>>>                 false;
>>>         end if;
>>>
>>> I'm not familiar with Maple, but is there any reason to write this
>>> instead of just
>>>
>>>         max(op(%)) <= n;
>>>
>>> Franklin T. Adams-Watters
>>>
>>> -- 
>>> Seqfan Mailing list - http://list.seqfan.eu/
>>>
>>>
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