OFFSET
1,1
COMMENTS
It is a conjecture that this sequence is finite. A search around 2^n was done up to 2^1500.
MATHEMATICA
Flatten[Table[Select[2^n-Range[17], AllTrue[{#, #+18}, PrimeQ]&], {n, 4, 80}]]// Sort (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 04 2019 *)
PROG
(Magma)
//Program finds primes separated by an even number (called gap) which
//have a power of two between them. Program starts with the smallest
//power of two above gap. Primes less than this starting point can be
//checked by inspection.
gap:=18;
start:=Ilog2(gap)+1;
for i:= start to 1000 do
powerof2:=2^i;
for k:=powerof2-gap+1 to powerof2-1 by 2 do
if (IsPrime(k) and IsPrime(k+gap)) then k;
end if;
end for;
end for;
CROSSREFS
KEYWORD
nonn
AUTHOR
Brad Clardy, Feb 23 2013
STATUS
approved