More digital silliness
David W. Cantrell
DWCantrell at sigmaxi.net
Wed Jan 9 21:41:57 CET 2008
Bob Hearn wrote:
> There's probably some simple reason that the answer is no, but
> empirically, there are no such numbers < 10^16.
I suppose that may be true if you are restricted to the decimal
system, but DWW said nothing about such a restriction. Using an
appropriate base, all rotations of 1111 are square, and of course,
using that same base, so are all rotations of 4444.
David W. Cantrell
> On Jan 9, 2008, at 2:33 PM, David W. Wilson wrote:
>
>> Let an n-digit number be valid if it does not start or end with 0.
>>
>> Let a rotation of n be gotten by rotating its digits. Thus the
>> rotations of 256 are 256, 562 and 625.
>>
>> We note that 256 has two valid square rotations, 256 and 625.
>>
>> Is there a number with more than two valid square rotations?
Make that 10^18.
Bob
On Jan 9, 2008, at 3:24 PM, Bob Hearn wrote:
> There's probably some simple reason that the answer is no, but
> empirically, there are no such numbers < 10^16.
>
> Bob Hearn
>
>
> On Jan 9, 2008, at 2:33 PM, David W. Wilson wrote:
>
>> Let an n-digit number be valid if it does not start or end with 0.
>>
>> Let a rotation of n be gotten by rotating its digits. Thus the
>> rotations of 256 are 256, 562 and 625.
>>
>> We note that 256 has two valid square rotations, 256 and 625.
>>
>> Is there a number with more than two valid square rotations?
>
More information about the SeqFan
mailing list