[seqfan] Re: sequence challenge

[Alois Heinz]

a:= n-> (<<0|1|0>,
<0|0|1>,
<1|-3|5>> ^n)[1,1];
gives: 1, 0, 0, 1, 5, 22, 96, 419, 1829, 7984, 34852, 152137, 664113, 
2899006, 12654828, 55241235

is not in the OEIS.

Alois

Am 21.11.2011 18:02, schrieb Peter Lawrence:
>
> an odd story: I was trying to find a 3x3 matrix for Tri-bonacci numbers
> like the [[1,0][1,1]]**n for generating Fibonacci numbers, and finally
> figured one out through logic. I initially thought I would find one by
> trial-and-error, but that didn't work for me. Here's the odd part, all
> the trial-and-error matricies I tried did end up matching something in
> the OEIS !
>
> so here is the challenge, find a 3x3 integer matrix with "smallish"
> elements whose powers generate a sequence that is _not_ in the OEIS.
>
> (taking the [0,0]'th element of each matrix as the sequence).
>
>
> -Peter Lawrence.
>