Nothing new under the sun
Richard Guy
rkg at cpsc.ucalgary.ca
Thu Mar 30 19:13:45 CEST 2006
Thankyou! I'm copying it to the
original addressees. R.
On Thu, 30 Mar 2006, Robert G. Wilson v wrote:
> Dear Sir,
>
> But they are not identical.
>
> A025480 uses the natural numbers for a(2n)=n
> whereas A108202 a(2n)=A007376(n): The almost-natural
> numbers: write n in base 10 and juxtapose digits.
>
> This then produces two different sequences.
> Let me place them one over the other.
>
> 0, 0, 1, 0, 2, 1, 3, 0, 4, 2, 5, 1, 6, 3, 7, 0, 8, 4,
> 9, 2, 10, 5, 11, 1, 12, 6, 13, 3, 14, 7, 15, 0, 16,
> 8, 17, 4, 18, 9, 19, 2, 20, 10, 21, 5, 22, 11, 23, 1,
> 24, 12, 25, 6, 26, 13, 27, 3, 28, 14, 29, 7, 30, 15,
> 31, 0, 32, 16, 33, 8, 34, 17, 35, 4, 36, 18, 37, 9,
> 38, 19, 39, 2, 40, 20, 41, 10
> 0, 0, 1, 0, 2, 1, 3, 0, 4, 2, 5, 1, 6, 3, 7, 0, 8, 4,
> 9, 2, 1, 5, 0, 1, 1, 6, 1, 3, 1, 7, 2, 0, 1,
> 8, 3, 4, 1, 9, 4, 2, 1, 1, 5, 5, 1, 0, 6, 1,
> 1, 1, 7, 6, 1, 1, 8, 3, 1, 1, 9, 7, 2, 2,
> 0, 0
>
> I hope this clarifies things.
>
> Sincerely yours,
>
> Robert G. 'Bob' Wilson, V
> ATP / CF & GI
>
> Richard Guy wrote:
>> Sequences A025480 and A108202 are identical
>> and much older than the references given
>> there. They are the nim-values for heaps of
>> n beans in the game where you're allowed to
>> take up to half of the beans in a heap.
>>
>> I can't quote chapter and verse, but this
>> has been well known to those who well know
>> it for half a century. R.
>>
>>
>
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