[seqfan] Re: Comma-digit swap
Eric Angelini
Eric.Angelini at kntv.be
Wed Sep 28 09:05:09 CEST 2011
Many thanks to Maximilian
and Graeme!
Best,
E.
Envoyé d'un iPhone
Le 28 sept. 2011 à 02:43, "Graeme McRae" <g_m at mcraefamily.com> a écrit :
> In base 2, the sequences are
> P=7,29,59,79,113,131,137,149,...
> S=15,27,55,95,99,135,147,171,...
>
> In base 3,
> P=2,7,13,23,17,19,29,41,67,43,...
> S=8,4,14,16,25,32,34,44,40,49,...
>
> --Graeme McRae,
> Palmdale, CA
>
> On Sep 27, 2011, at 8:28 AM, Eric Angelini <Eric.Angelini at kntv.be> wrote:
>
>> Hello Seqfans,
>>
>> S = 21,12,32,91,33,1,72,111,92,231,132,272,291,273,14,15,4,34,...
>> P = 2,11,23,29,13,3,17,211,19,223,113,227,229,127,31,41,5,43,4...
>>
>> S contains only non-primes which differ one from another;
>> P contains only primes which differ one from another;
>> and S becomes P if you permute each comma of S with its
>> closest digit on the left.
>>
>> Is the above start of S the lexicographically first such one?
>> In building S we have obeyed these rules:
>>
>> a) Write S and P with a(n) and a(n+1) only separated by a comma;
>> b) a(n) is the smallest non-prime not yet present in S such that
>> permuting the comma which follows a(n) with the last digit
>> of a(n) will produce a prime not yet present in P.
>>
>> Best,
>> É.
>>
>>
>> _______________________________________________
>>
>> Seqfan Mailing list - http://list.seqfan.eu/
>
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