A222424 Numbers n such that n and n + 14 are prime and there is a power of two in the interval (n,n+14).

3, 5, 23, 29, 53, 59, 509, 1019, 2039, 262133, 262139, 536870909, 73786976294838206459, 2787593149816327892691964784081045188247543

Offset

1,1

Comments

It is a conjecture that this is a finite sequence. A search was conducted out to 2^1500.

Links

Table of n, a(n) for n=1..14.

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:=14;
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

Cf. A153417, A221211.

Sequence in context: A270912 A137084 A271347 * A067256 A136891 A296920

Adjacent sequences: A222421 A222422 A222423 * A222425 A222426 A222427

Keyword

nonn

Author

Brad Clardy, Feb 24 2013

Status

approved