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A305318 Numbers k such that A071866(k)=3. 1

%I

%S 2,3,5,6,7,10,11,12,13,17,18,20,21,24,25,26,28,29,30,33,35,36,37,41,

%T 42,43,44,45,49,50,52,53,57,58,59,60,64,65,67,69,70,73,74,78,79,81,82,

%U 83,84,87,88,89,98,99,100,104,105,109,110,111,112,113,115,116,120,121,122,125,129,130,133

%N Numbers k such that A071866(k)=3.

%C All terms are in A066940. The first member of A066940 not in this sequence is 61.

%H Robert Israel, <a href="/A305318/b305318.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A000720(A275697(n+1)). - _Robert Israel_, May 31 2018

%p select(n -> nops(convert(ithprime(n+1)/ithprime(n),confrac))=3, [$1..1000]);

%o (PARI) isok(n) = length(contfrac(prime(n+1)/prime(n))) == 3; \\ _Michel Marcus_, May 31 2018

%Y Cf. A000720, A066940, A071866, A275697. Contains A029707.

%K nonn

%O 1,1

%A _Robert Israel_, May 29 2018

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Last modified August 12 12:09 EDT 2020. Contains 336439 sequences. (Running on oeis4.)