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A094896 If 4*n+1 is prime and 4*n+3 is not prime then a(n)=4*n+1, else a(n)=0.

%I A094896 #15 Sep 08 2022 08:45:13
%S A094896 0,0,0,13,0,0,0,0,0,37,0,0,0,53,0,61,0,0,73,0,0,0,89,0,97,0,0,109,113,
%T A094896 0,0,0,0,0,0,0,0,0,0,157,0,0,0,173,0,181,0,0,193,0,0,0,0,0,0,0,0,229,
%U A094896 233,0,241,0,0,0,257,0,0,0,0,277,0,0,0,293,0,0,0,0,313,317,0,0,0,0,337,0,0
%N A094896 If 4*n+1 is prime and 4*n+3 is not prime then a(n)=4*n+1, else a(n)=0.
%p A094896 A094896 := proc(n)
%p A094896     if isprime(4*n+1) and not isprime(4*n+3) then
%p A094896         4*n+1;
%p A094896     else
%p A094896         0;
%p A094896     end if;
%p A094896 end proc:
%p A094896 seq(A094896(n),n=0..86) ; # _R. J. Mathar_, Nov 15 2019
%t A094896 a=Table[If[PrimeQ[4*n+1]==True&&PrimeQ[4*n+3]==False, 4*n+1, 0], {n, 0, 200}]
%o A094896 (Magma) [IsPrime(4*n+1) and not IsPrime(4*n+3) select 4*n+1 else 0:n in [0..86]]; // _Marius A. Burtea_, Nov 15 2019
%Y A094896 Cf. A005098, A095277, A094897.
%K A094896 nonn
%O A094896 0,4
%A A094896 _Roger L. Bagula_, Jun 14 2004