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%I #6 Apr 25 2020 16:06:54
%S 22,24,36,60,1678
%N Numbers n such that 2^(2*n-43)-43 is prime.
%e 2^(2*36-43)-43=536870869, 2^(2*60-43)-43=151115727451828646838229, ...
%t q=43;For[i=q,i<=q,a={};Do[x=2^(2*n-i)-i;If[PrimeQ[x],AppendTo[a,n]],{n,13^3}];Print["2^(2*n-",i,")-",i," ",a];i=i+2]
%t Select[Range[1680],PrimeQ[2^(2#-43)-43]&] (* _Harvey P. Dale_, Apr 25 2020 *)
%o (PARI) is(n)=isprime(2^(2*n-43)-43) \\ _Charles R Greathouse IV_, Jun 13 2017
%K nonn,easy
%O 1,1
%A _Vladimir Joseph Stephan Orlovsky_, May 13 2008