Not yet in OEIS: Product of odd divisors of n?

Jonathan Post jvospost3 at
Thu Jun 26 20:44:08 CEST 2008

Thank you, Vladeta Jovovic and David Wilson

I'd done a sloppy, incomplete job.

I realized at the time I emailed seqfans the first formula that
Vladeta Jovovic gave:
a(n) = sqrt(n^od(n)/2^ed(n))
but not the one that he derived from that.

I realized at the time I emailed seqfans that a(n) could be expressed
in terms of A000265 and A007955, which is why I listed them as 2 of
the 5 xrefs.  But I did not put the pieces together, and these two
fine people did the heavy lifting and deserve credit.

If, that is, the sequence should be submitted to OEIS.  Perhaps as
coauthored by 3 of us?

Once again, we've all seen OEIS and seqfans as collaborationware.  Well done!

On 6/26/08, David Wilson <davidwwilson at> wrote:
> Also, a(n) = A007955(A000265(n)).

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