[seqfan] Re: Nonmembers of Range of Euler Phi Function

T. D. Noe noe at sspectra.com
Sun Sep 19 20:24:05 CEST 2010


At 12:47 PM -0500 9/19/10, Ray Chandler wrote:
>> I want to submit a sequence whose nth term is, if it exists,
>> the smallest positive integral multiple of 2^n not in the
>> range of the Euler phi function.
>> I know the terms up to n=5 (so the offset is n=0): 3, 14, 68,
>> 152, 304, 608
>>
>
>Using Tony Noe's b-file from A005277, sequence continues
>3, 14, 68, 152, 304, 608, 1984, 3968, 12032, 24064, ...

Please ignore the last comment.

Calculating up to n=17, I find that these numbers all have the form 2^n *
p, where p is 3, 7, 17, 19, 31, 47.  It's not clear what sequence p is.
Might be A064699

Tony





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