[seqfan] Re: Question regarding A069570
Andrew Weimholt
andrew.weimholt at gmail.com
Thu Jun 17 12:48:05 CEST 2010
On Thu, Jun 17, 2010 at 3:17 AM, Jeremy Gardiner
<jeremy.gardiner at btinternet.com> wrote:
>
> My interpretation is that,
>
> 1st digit is either a divisor or a multiple of 1,
> 2nd digit is either a divisor or a multiple of 2,
> 3rd digit is either a divisor or a multiple of 3, etc.
>
> e.g. Why are 13 and 122 in the sequence, among others?
>
It appears that by "1st digit", the author means "least significant digit",
so with 13, the first digit is 3 and the second is 1.
There is a typo in the sequence: ...19, 18, 19,... should be
...17, 18, 19,...
The title should be reworded to something like
"Numbers in which the n-th least significant digit is either a divisor
or a non-zero multiple of n."
(added "least significant" and "non-zero")
Sequences A069571 through A069574 should include the same
clarifications in their titles.
Andrew
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