[seqfan] Re: A129066: First term non-multiple of 5?

[Max Alekseyev]

There are no terms >1 that are not multiples of 5.

If n is such a term and p is its smallest prime divisor (p<>5). Then
Pisano period per(p) divides n.
But since per(p) divides p-1 or p+1, n has even smaller divisor than
p, a contradiction.

Regards,
Max

On Sun, Nov 1, 2009 at 2:02 PM, zak seidov <zakseidov at yahoo.com> wrote:
> Anyone may wish to find
> the first term
> that isn't multiple of 5 ?
>
> Zak
>
> PS Note that I added 1 as the first term,
> so we look for term(s) > 1.
>
> %S A129066 1 (* added by me *), 5,25,125,625,3125,15625,75025,78125,375125,390625,1875625,1953125,9378125,
> %T A129066 9765625,46890625,48828125
> %N A129066 Numbers n such that n divides Fibonacci(n) with multiples of 12 excluded.
> %C A129066 a(n) includes all terms of A023172(n) with terms 12*A072378(n) excluded.
>
>
>
>
>
>
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