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A277376 Each prime p is followed by p nonprimes. 1


%S 2,1,4,3,6,8,9,5,10,12,14,15,16,7,18,20,21,22,24,25,26,11,27,28,30,32,

%T 33,34,35,36,38,39,40,13,42,44,45,46,48,49,50,51,52,54,55,56,57,17,58,

%U 60,62,63,64,65,66,68,69,70,72,74,75,76,77,78,80,19,81,82,84,85,86,87,88,90,91,92,93,94,95,96,98,99,100

%N Each prime p is followed by p nonprimes.

%C The sequence starts with a(1) = 2 and was always extended with the smallest integer not yet present that does not lead to a contradiction.

%H Jean-Marc Falcoz, <a href="/A277376/b277376.txt">Table of n, a(n) for n = 1..7162</a>

%e As a(1) = 2, we take for a(2) and a(3) the nonprimes "1" and "4"; we then extend the sequence with a(4) which must be the smallest prime not yet present: this is "3"; we take for a(5), a(6) and a(7) the 3 smallest nonprimes not yet present: they are 6, 8 and 9; we then extend the sequence with the smallest prime available, which is a(8) = 5. Etc.

%p p:= 0: q:= 0: res:= NULL:

%p for i from 1 to 20 do

%p p:= nextprime(p);

%p res:= res, p;

%p count:= 0;

%p while count < p do

%p q:= q+1;

%p if not isprime(q) then

%p res:= res, q;

%p count:= count+1;

%p fi

%p od

%p od:

%p res; # _Robert Israel_, Oct 19 2016

%K nonn

%O 1,1

%A _Eric Angelini_ and _Jean-Marc Falcoz_, Oct 11 2016

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Last modified June 14 21:27 EDT 2021. Contains 345041 sequences. (Running on oeis4.)