[seqfan] Re: Champernowne sieved

[Neil Sloane]

Lovely! Paul Tek or Alois Heinz (who extended A228326-8) - could
you enter and extend these two?
Thanks
Neil


On Sun, Aug 25, 2013 at 7:03 PM, Eric Angelini <Eric.Angelini at kntv.be>wrote:

>
> Hello SeqFans,
> consider http://oeis.org/A033307
> (decimal expansion of Champernowne's constant):
> 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 0, 1, 1, 1, 2, 1, 3, 1, 4, 1, 5, 1, 6, 1, 7,
> 1, 8, 1, 9, 2, 0, 2, 1, 2, 2, 2, 3, 2, 4, 2, 5, 2, 6, 2, 7, 2, 8, 2, 9, 3,
> 0, 3, 1, 3, 2, 3, 3, 3, 4, 3, 5, 3, 6, 3, 7, 3, 8, 3, 9, 4, 0, 4, 1, 4, 2,
> 4, 3, 4, 4, 4, 5, 4, 6, 4, 7, 4, 8, 4, 9, 5, 0, 5, 1, 5, 2, 5, 3, 5, 4, 5,
> 5, 5, 6, 5,...
>
> Now erase a digit when it is placed
> between two digits having the same parity -- and
> do this repeatedly.
>
> Example:
> 1,2,3,... erase 2
> You get now:
> 1,3,4,5,... erase 4
> You get now:
> 1,3,5,... erase 3
> You get now:
> 1,5,6,7,... erase 6
> You get now:
> 1,5,7,... erase 5 etc.
>
> Two seq might be of interest;
> 1) R, the surviving digits:
>
> R=1,9,2,2,9,9,4,4,9,9,6,6,9,9,8,8,9,1,0,0,1,1,0,2,1,1,0,4,1,1,0,6,1,1,0,8,1,1,2,0,1,1,2,2,3,1,2,2,1,9,2,2,9,9,4,4,9,9,6,6,9,9,8,8,9,1,0,0,1,1,0,2,1,1,0,4,1,1,0,6,1,1,0,8,1,1,2,0,1,2,2,3,1,2,2,5,1,2,2,7,1,2,2,9,1,4,0,1,4,4,3,1,4,4,5,1,4,4,7,1,4,4,9,1,6,0,1,1,6,2,1,...
>
> 2) U, the original "untouched" natural integers:
> U=1,29,49,69,89,102,104,106,108,120,140,160,162,...
>
> (R and U computed by hand... don't
> trust those figures too much)
> Best,
> É.
>
>
>
>
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>
> Seqfan Mailing list - http://list.seqfan.eu/
>



-- 
Dear Friends, I have now retired from AT&T. New coordinates:

Neil J. A. Sloane, President, OEIS Foundation
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