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%I A090670 #14 May 31 2021 21:11:14
%S A090670 3,5,7,11,13,17,23,25,31,35,37,41,43,53,55,65,67,71,77,83,85,91,97,
%T A090670 101,107,113,115,121,127,133,137,143,155,157,167,175,181,185,191,193,
%U A090670 211,217,221,223,233,235,241,245,247,251,253,263,275,283,287,295,301,305
%N A090670 Odd numbers k such that 2*k-3 is a prime of the form 4*j+3.
%D A090670 M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
%D A090670 Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997
%H A090670 Vincenzo Librandi, <a href="/A090670/b090670.txt">Table of n, a(n) for n = 1..10000</a>
%F A090670 a(n) = A087915(n)+3.
%t A090670 okQ[n_]:=Module[{x=2n-3},PrimeQ[x]&&IntegerQ[(x-3)/4]]; Select[Range[1,315,2],okQ]  (* _Harvey P. Dale_, Jan 12 2011 *)
%Y A090670 Cf. A087915, A002145.
%Y A090670 Cf. A050415 (primes of the form 2^k-3).
%K A090670 easy,nonn
%O A090670 1,1
%A A090670 _Giovanni Teofilatto_, Dec 17 2003
%E A090670 Offset changed from 0 to 1 by _Vincenzo Librandi_, Dec 13 2011

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