[seqfan] Re: Resurrect A090566?

[Neil Sloane]

David, Thanks for that message. I have undeaded A090566 and extended and
corrected it with your terms. And I added cross-refs between them. Nice
work!

Best regards
Neil

Neil J. A. Sloane, President, OEIS Foundation.
11 South Adelaide Avenue, Highland Park, NJ 08904, USA.
Also Visiting Scientist, Math. Dept., Rutgers University, Piscataway, NJ.
Phone: 732 828 6098; home page: http://NeilSloane.com
Email: njasloane at gmail.com


On Sat, Nov 21, 2015 at 12:00 AM, David Wilson <davidwwilson at comcast.net>
wrote:

> A082209 is defined as:
>
>
>
> a(1) = 1, a(n+1) = smallest k with concat(a(n), k) square.
>
>
>
> A090566 was deaded as an erroneous version of A082209. But I could argue
> that A090566 was meant to be a different sequence, namely:
>
>
>
> a(1) = 1, a(n+1) = smallest k > a(n) with concat(a(n), k) square.
>
>
>
> Observe that A090566 in increasing and that concatenating adjacent elements
> of A090566 gives square numbers. This supports my interpretation.
>
> By this new definition, A090566 is still incorrect starting at a(5),
> perhaps
> due to computation error. Corrected, I believe it begins
>
>
>
> 1,6,25,281,961,6201,59409,187600,730641,4429444,28600025,85336064
>
>
>
> This sequence does not occur elsewhere in the OEIS, so I propose to
> resurrect A090566 with this new definition (or create a new sequence if
> this
> is unacceptable).
>
>
>
> I computed the above elements using a brute force C++ program, but with the
> appropriate power tools, e.g. Mma, and a little cleverness, I think this
> sequence could be generated quite efficiently. Anyone up to verifying and
> extending my values?
>
>
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