[seqfan] Re: Nice nontrivial integer sequence
M. F. Hasler
oeis at hasler.fr
Sun Mar 12 05:35:26 CET 2023
On Sat, Mar 11, 2023, 22:52 Tim Peters <tim.peters at gmail.com> wrote:
> The page for A360477
>
> https://oeis.org/A360447
>
> contains
>
> FORMULA a(n) = a(n-1) + a(n+1) if a(n+1) < a(n)
>
> I expect "a formula" to show a way to compute a(n), but that's not what
> this is.
Not always. Formulas comprise inequalities, asymptotic behavior, and other
properties.
It appears to be a claim about 3 consecutive terms in some cases, but it's
> not a true claim.
Yes you are right. The formula should have been deleted earlier. I have
done it now.
I think the first place it fails is at n=18:
> n a(n)
> 17 59586
> 18 33733
> 19 7880
Then a(19) < a(18), but a(18) isn't anywhere near a(17) + a(19).
>
I agree.
-Maximilian
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