[seqfan] Re: 1862

[Éric Angelini]

You are absolutely right, Maximilian --
and Jean-Marc's list (sent to me in a
private mail) started indeed with 1,2,3,
4,5,6,7,8,9,10,11...
His count was then 1872.
And as 1872 wasn't in the list, I've
cheated (a bit)!

à+
É.
Catapulté de mon aPhone


> Le 8 oct. 2019 à 13:06, M. F. Hasler <seqfan at hasler.fr> a écrit :
> 
>> On Mon, Oct 7, 2019, 12:59 Neil Sloane wrote:
>> 
>> That sequence is now A328075.  Thank you Éric!
>> 
> 
> The sequence starts presently with 90 trivial terms 10..99 : in a two digit
> number all differences are distinct since there is only one.
> Technically speaking, the single digit numbers also satisfy the property
> that all differences are distinct. So they are also in the sequence
> But rather than to add these in front, one might have chosen offset = 90
> (if not 100) and start with or near the nontrivial terms.
> 
> - Maximilian
> 
>> On Mon, Oct 7, 2019 at 5:27 AM Éric Angelini wrote:
>> 
>>> 1862.
>>> Pick any two digits: their absolute
>>> difference is unique (for 1862). Indeed
>>> the set of all 2-digit abs diffs of 1862
>>> is 7,5,1,2,6,4, with no repeated element.
>>> 
>>> The same with 10 or 1037
>>> (10 --> 1 and 1037 --> 1,3,2,4,7,6).
>>> 
>>> With a(1) = 10, the seq has precisely...
>>> ... 1862 terms. Which is the header
>>> of this msg. (Yes, we love selfref')
>>> Best,
>>> É.
>>> (many thanks to Jean-Marc Falcoz, in copy)
>> 
> 
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