[seqfan] Re: correcting A181539
N. J. A. Sloane
njas at research.att.com
Wed Nov 3 15:44:23 CET 2010
Bob Wilson wrote to me about this sequence,
pointing out that it did not
match the definition, and offering to edit it.
Bob, what did you come up with?
Neil
>The current A181539 does not seem to match its definition:
>for example, why a(2)=51 and not a(2)=49 (let alone a(2)=1)?
>I would rather change the definition to:
>a(n) = smallest number m > 1 such that m^2 == 1 (mod 10^n)
>that would give a sequence:
>9, 49, 249, 1249, 18751, 218751, 781249, 24218751, 74218751,
>1425781249, 13574218751, 163574218751, 163574218751, 19836425781249,
>19836425781249, 2480163574218751, 12519836425781249,
>12519836425781249, 487480163574218751, 15487480163574218751,
>215487480163574218751, 215487480163574218751, 4784512519836425781249,
>45215487480163574218751, 45215487480163574218751
>Regards,
>Max
>On Wed, Nov 3, 2010 at 8:29 AM, Richard Mathar
><mathar at strw.leidenuniv.nl> wrote:
>>
>> Is there a way to keep the terms in http://oeis.org/classic/A181539
>> (current definition m: m^2 =1 (mod 10^n) by changing the definition? I'd expect
>> some corresponding terms of http://oeis.org/classic/A181607 Â to appear, but I
>> cannot figure out which modification in A181539 would do that
>> selection/matching.
>>
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