A188677 Primes p such that the minimum value of |p-2^x|, x>0, is also a prime.

11, 13, 19, 23, 29, 37, 43, 53, 59, 61, 67, 71, 83, 97, 109, 131, 139, 151, 157, 181, 197, 227, 233, 239, 251, 263, 269, 293, 317, 353, 359, 383, 409, 433, 439, 499, 509, 523, 541, 571, 601, 613, 619, 643, 661, 691, 709, 739, 751, 773, 797, 827, 857

Offset

1,1

Comments

Originally submitted by Benoit Cloitre, Dec 17 2002 as A078686 and corrected by Robert G. Wilson v, Apr 08 2011.

Links

Table of n, a(n) for n=1..53.

Formula

Intersection of A086081 and A091932. - Robert G. Wilson v, May 27 2011

Mathematica

fQ[n_] := Block[{x = Floor@ Log2@ n}, PrimeQ@ Min[n - 2^x, 2^(x+1) - n]]; Select[ Prime@ Range@ 150, fQ] (* Robert G. Wilson v, Apr 08 2011 *)

Prog

(PARI) is(n)=if(isprime(n), my(x=log(n)\log(2)); isprime(min(abs(n-1<<x), abs(n-2<<x))), 0) \\ Charles R Greathouse IV, Jan 10 2013

Crossrefs

Cf. A078686, A086081, A091932.

Sequence in context: A214629 A330696 A103803 * A068801 A215504 A342406

Adjacent sequences: A188674 A188675 A188676 * A188678 A188679 A188680

Keyword

nonn

Author

Benoit Cloitre & Robert G. Wilson v, Apr 08 2011

Status

approved