Is my number a de Polignac number?
Japt, 9 14 13 bytes

o!²mnU dj |Uv


Test it online! or Find all de Polignac integers under 1000.

Outputs 1 for falsy inputs and 0 for truthy.

Explanation

 o!²  mnU dj |Uv
Uo!p2 mnU dj |Uv  : Ungolfed
                  : Implicit: U = input integer (e.g. 9)
Uo                : Create the range [0..U), and map each item X to
  !p2             :   2 ** X.               [1, 2, 4, 8, 16, 32, 64, 128, 256]
      m           : Map each of these powers of 2 by
       nU         :   subtracting from U.   [8, 7, 5, 1, -7, -23, -57, -119, -247]
          d       : Return whether any item in the result is
           j      :   prime.                (5 and 7 are, so `true`)
             |    : Take the bitwise OR of this and
              Uv  :   U is divisble by (missing argument = 2).
                  : This gives 1 if U cannot be represented as p + 2^n or if U is even.
                  : Implicit: output result of last expression