[seqfan] Re: Error in the example for A003313
Rob Arthan
rda at lemma-one.com
Sat Jul 20 16:10:51 CEST 2013
On 17 Jul 2013, at 19:24, Rob Arthan wrote:
>
> On 16 Jul 2013, at 23:58, Max Alekseyev <maxale at gmail.com> wrote:
>
>> On Tue, Jul 16, 2013 at 6:25 PM, Rob Arthan <rda at lemma-one.com> wrote:
>>> The example in A003313 "Length of shortest addition chain for n" is incorrect (or, at best, very misleading). It gives an ASCII-art picture of a tree with positive integer node labels and says that a(n) is the depth of the node with label n in the tree. This is taken from Knuth, but the statement is claiming much more than Knuth does.
>>
>> What exactly does Knuth state about this tree
> See my last post in this thread for the precise rules Knuth gives for constructing the tree.
>>
>>> In fact, it is not possible to extend this tree to include.all values of n.
>>
>> Then it would make sense to add the sequence (if it is not yet in
>> OEIS) of those n that appear in this tree as well as the sequence of
>> those n that are missing in the tree.
>
> I agree. When I have a minute I will look into contributing these sequences.
In fact they are already there: A114622 and A113945.
Regards,
Rob.
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