[seqfan] Re: A081650

[Robert G. Wilson v]

Thank you. Bob.

-----Original Message-----
From: SeqFan [mailto:seqfan-bounces at list.seqfan.eu] On Behalf Of M. F. Hasler
Sent: Tuesday, November 17, 2015 10:57 AM
To: Sequence Fanatics Discussion list
Subject: [seqfan] Re: A081650

Don, Robert,
I edited the title of this sequence to match the data and propose the other version as https://oeis.org/draft/A260709.
- Maximilian

On Tue, Nov 17, 2015 at 3:04 AM,  <israel at math.ubc.ca> wrote:
> From the program, it seems to be that "(mod k^2)" is being used as a 
> function rather than a relation, so even though 52 is congruent to a 
> square mod 9 (i.e. 52 == 4^2 mod 9), 52 mod 9 = 7 is not a square.
>
> Since this is an old sequence, I don't think its Data should be 
> changed, rather the definition should be clarified. The sequence 2, 5, 
> 13, 52, 241, 241, 436, 1009, 1009, 1009, ... corresponding to 
> congruence as a relation does not seem to be in the OEIS: perhaps you'd like to contribute it.
>
> Cheers,
> Robert
>
> On Nov 16 2015, Don Reble wrote:
>
>> Seqfans:
>>
>> > %S A081650 2,5,13,73,409,801,1584,2241,30601,30601,78409,156825, ...
>> > %N A081650 Least nonsquare congruent to i^2 (mod k^2) for all 0<k<=n,
>> >            i being any integer.
>> > %O A081650 1,1
>>
>>   Why is a(4)=73, instead of 52?

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