[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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> 
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