cp's OEIS Frontend

A094897 If 4*n+1 is not prime and 4*n+3 is prime then a(n)=4*n+3, else a(n)=0.

%I A094897 #14 Sep 08 2022 08:45:13
%S A094897 3,0,11,0,0,23,0,0,0,0,0,47,0,0,59,0,67,71,0,79,83,0,0,0,0,0,107,0,0,
%T A094897 0,0,127,131,0,0,0,0,0,0,0,163,167,0,0,179,0,0,191,0,0,0,0,211,0,0,
%U A094897 223,227,0,0,239,0,0,251,0,0,263,0,0,0,0,0,0,0,0,0,0,307,311,0,0,0,0,331,0
%N A094897 If 4*n+1 is not prime and 4*n+3 is prime then a(n)=4*n+3, else a(n)=0.
%p A094897 A094897 := proc(n)
%p A094897     if not isprime(4*n+1) and isprime(4*n+3) then
%p A094897         4*n+3;
%p A094897     else
%p A094897         0;
%p A094897     end if;
%p A094897 end proc:
%p A094897 seq(A094897(n),n=0..86) ; # _R. J. Mathar_, Nov 15 2019
%t A094897 a=Table[If[PrimeQ[4*n+1]==False&&PrimeQ[4*n+3]==True, 4*n+3, 0], {n, 0, 200}]
%o A094897 (Magma) [IsPrime(4*n+3) and not IsPrime(4*n+1) select 4*n+3 else 0:n in [0..85]]; // _Marius A. Burtea_, Nov 15 2019
%Y A094897 Cf. A045751, A095278, A094896.
%K A094897 nonn
%O A094897 0,1
%A A094897 _Roger L. Bagula_, Jun 14 2004