A053878

[Mitchell Harris]

On Thu, 9 Jun 2005, Jud McCranie wrote:

>At 09:44 PM 6/9/2005, you wrote:
>>At 06:43 PM 6/9/2005, David Wilson wrote:
>>>Can we extend A053878 out far enough to show it is not multiplicative?
>>
>>
>>a(52) = 2 (the ratio is 17/15), but a(4)=1 and a(13)=1, so it is not 
>>multiplicative.
>>
>>The first few non-zero terms are #25, 52, 53, 54, 64, which are 7, 2, 3, 
>>5, 4 (resp),
>
>Actually I failed to notice that the offset in A53878 is 2.
>
>So the first terms that aren't 1 are #26, 53, 54, 55, 65 so a(26)= 
>a(2*13)=7 shows that it isn't multiplicative.  At any rate, depending on 
>how you define the offset, one of these terms shows that it isn't "mult".

Yes, the offset is somewhat arbitrary here. If the offset is such that
a(26)=7 then already it is not multiplicative, but if it is such that
a(25)=7 (which is how my search program figured it) then all that needs to
be checked is the corresponding a(50), which I think you have calculated
to be 1, confirming the nonmultiplicativity.

-- 
Mitch Harris