Seq.s A050150 & A062090.

[Klaus Brockhaus]

Robert G. Wilson v schrieb:
> 
> Sequence Fanatics,
> 
>         A062090 is a(1) = 1, a(n)= smallest odd number which does not
> divide the product of all previous terms.
> 
>         A050150 is Odd numbers with prime number of divisors.
> 
>         They both begin: 3, 5, 7, 9, 11, 13, 17, 19, 23, 25, 29, 31, 37,
> 41, 43, 47, 49, 53, 59, 61, 67, 71, 73, 79,
> 81, 83, 89, 97, 101, 103, 107, 109, ..., .
> 
>         In the comments section of A050150 it says that "This sequence
> differs from A062090 by one term, "81", so far." I do not know who said
> this nor do I care, but it is wrong. The two sequences match except for
> the initial 1 which is needed to begin A062090 up to 729. It appears in
> A050150 but not in A062090. Then 6561 appears in A062090 but not in
> A050150. I'll push this further. Any comments?
> 
> Sincerely,
> 
> Robert G. "Bob" Wilson, v

A PARI program produced this result (for integers <= 800000):
in A050150 but not in A062090: [729, 15625, 59049, 117649, 531441];
in A062090 but not in A050150: [1, 6561, 390625].
It confirms the values given by Robert G. Wilson.

Klaus Brockhaus