ClearAll[Jacobsthal, JacobsthalLucas, JacobsthalOblong]
Jacobsthal[n_]:=(2^n-(-1)^n)/3
JacobsthalLucas[n_]:=2^n+(-1)^n
JacobsthalOblong[n_]:=Jacobsthal[n]Jacobsthal[n+1]
Jacobsthal[Range[0, 29]]
JacobsthalLucas[Range[0, 29]]
JacobsthalOblong[Range[0, 19]]
n=0;
i=0;
Reap[While[n<20,
 If[
  PrimeQ[Jacobsthal[i]]
 ,
  Sow[{i,Jacobsthal[i]}];
  n++;
 ];
 i++;
]][[2,1]]//Grid