The cache is not at the posted coordinates, and there is nothing for you to find there.
Recently I hid another DAMN cache.
A = 1-2+E
C = 1-7-7
D = 7
E = 1+1-4
F = 7
Cache can be found at N 51 25.ABC W 002 22.DEF
This cache is part of a series of puzzle caches hidden in the same area, which I've called the Lansdown Puzzle Series. They make an "L" shape on the map. See bookmark for the complete list.
You can validate your puzzle solution with certitude.